diff --git a/browser/installer/windows/nsis/installer.nsi b/browser/installer/windows/nsis/installer.nsi
index ff902b74fd97c..d5423881b35c3 100755
--- a/browser/installer/windows/nsis/installer.nsi
+++ b/browser/installer/windows/nsis/installer.nsi
@@ -41,6 +41,7 @@ Var TmpVal
 Var InstallType
 Var AddStartMenuSC
 Var AddTaskbarSC
+Var AddQuickLaunchSC
 Var AddDesktopSC
 Var AddPrivateBrowsingSC
 Var InstallMaintenanceService
@@ -381,20 +382,22 @@ Section "-Application" APP_IDX
 
   ClearErrors
 
-  ; Apply LPAC permissions to install directory.
-  ${LogHeader} "File access permissions"
-  Push "Marker"
-  AccessControl::GrantOnFile \
-    "$INSTDIR" "(${LpacFirefoxInstallFilesSid})" "GenericRead + GenericExecute"
-  Pop $TmpVal ; get "Marker" or error msg
-  ${If} $TmpVal == "Marker"
-    ${LogMsg} "Granted access for LPAC to $INSTDIR"
-  ${Else}
-    ${LogMsg} "** Error granting access for LPAC to $INSTDIR : $TmpVal **"
-    Pop $TmpVal ; get "Marker"
-  ${EndIf}
+  ${If} ${AtLeastWin10}
+    ; Apply LPAC permissions to install directory.
+    ${LogHeader} "File access permissions"
+    Push "Marker"
+    AccessControl::GrantOnFile \
+      "$INSTDIR" "(${LpacFirefoxInstallFilesSid})" "GenericRead + GenericExecute"
+    Pop $TmpVal ; get "Marker" or error msg
+    ${If} $TmpVal == "Marker"
+      ${LogMsg} "Granted access for LPAC to $INSTDIR"
+    ${Else}
+      ${LogMsg} "** Error granting access for LPAC to $INSTDIR : $TmpVal **"
+      Pop $TmpVal ; get "Marker"
+    ${EndIf}
 
-  ClearErrors
+    ClearErrors
+  ${EndIf}
 
   ; Default for creating Start Menu shortcut
   ; (1 = create, 0 = don't create)
@@ -406,6 +409,16 @@ Section "-Application" APP_IDX
     StrCpy $AddPrivateBrowsingSC "1"
   ${EndIf}
 
+  ; Default for creating Quick Launch shortcut (1 = create, 0 = don't create)
+  ${If} $AddQuickLaunchSC == ""
+    ; Don't install the quick launch shortcut on Windows 7
+    ${If} ${AtLeastWin7}
+      StrCpy $AddQuickLaunchSC "0"
+    ${Else}
+      StrCpy $AddQuickLaunchSC "1"
+    ${EndIf}
+  ${EndIf}
+
   ; Default for creating Desktop shortcut (1 = create, 0 = don't create)
   ${If} $AddDesktopSC == ""
     StrCpy $AddDesktopSC "1"
@@ -494,11 +507,13 @@ Section "-Application" APP_IDX
   SetShellVarContext all  ; Set SHCTX to HKLM
 
   ; The keys below can be set in HKCU if needed.
+  ; For pre win8, the following keys should only be set if we can write to HKLM.
+  ; For post win8, the keys below can be set in HKCU if needed.
   ${If} $TmpVal == "HKLM"
     ; Set the Start Menu Internet and Registered App HKLM registry keys.
     ${SetStartMenuInternet} "HKLM"
     ${FixShellIconHandler} "HKLM"
-  ${Else}
+  ${ElseIf} ${AtLeastWin8}
     ; Set the Start Menu Internet and Registered App HKCU registry keys.
     ${SetStartMenuInternet} "HKCU"
     ${FixShellIconHandler} "HKCU"
@@ -559,7 +574,9 @@ Section "-Application" APP_IDX
   WriteRegDWORD HKCU ${MOZ_LAUNCHER_SUBKEY} "$INSTDIR\${FileMainEXE}|Telemetry" 1
 !endif
 
-  ${WriteToastNotificationRegistration} $TmpVal
+  ${If} ${AtLeastWin10}
+    ${WriteToastNotificationRegistration} $TmpVal
+  ${EndIf}
 
   ; Create shortcuts
   ${LogHeader} "Adding Shortcuts"
@@ -648,14 +665,16 @@ Section "-Application" APP_IDX
   ; Update lastwritetime of the Start Menu shortcut to clear the tile cache.
   ; Do this for both shell contexts in case the user has shortcuts in multiple
   ; locations, then restore the previous context at the end.
-  SetShellVarContext all
-  ${TouchStartMenuShortcut}
-  SetShellVarContext current
-  ${TouchStartMenuShortcut}
-  ${If} $TmpVal == "HKLM"
+  ${If} ${AtLeastWin8}
     SetShellVarContext all
-  ${ElseIf} $TmpVal == "HKCU"
+    ${TouchStartMenuShortcut}
     SetShellVarContext current
+    ${TouchStartMenuShortcut}
+    ${If} $TmpVal == "HKLM"
+      SetShellVarContext all
+    ${ElseIf} $TmpVal == "HKCU"
+      SetShellVarContext current
+    ${EndIf}
   ${EndIf}
 
   ${If} $AddDesktopSC == 1
@@ -684,6 +703,27 @@ Section "-Application" APP_IDX
     ${EndIf}
   ${EndIf}
 
+  ; If elevated the Quick Launch shortcut must be added from the unelevated
+  ; original process.
+  ${If} $AddQuickLaunchSC == 1
+    ${Unless} ${AtLeastWin7}
+      ClearErrors
+      ${GetParameters} $0
+      ${GetOptions} "$0" "/UAC:" $0
+      ${If} ${Errors}
+        Call AddQuickLaunchShortcut
+        ${LogMsg} "Added Shortcut: $QUICKLAUNCH\${BrandShortName}.lnk"
+      ${Else}
+        ; It is not possible to add a log entry from the unelevated process so
+        ; add the log entry without the path since there is no simple way to
+        ; know the correct full path.
+        ${LogMsg} "Added Quick Launch Shortcut: ${BrandShortName}.lnk"
+        GetFunctionAddress $0 AddQuickLaunchShortcut
+        UAC::ExecCodeSegment $0
+      ${EndIf}
+    ${EndUnless}
+  ${EndIf}
+
 !ifdef MOZ_OPTIONAL_EXTENSIONS
   ${If} ${FileExists} "$INSTDIR\distribution\optional-extensions"
     ${LogHeader} "Installing optional extensions if requested"
@@ -970,6 +1010,14 @@ FunctionEnd
 ################################################################################
 # Helper Functions
 
+Function AddQuickLaunchShortcut
+  CreateShortCut "$QUICKLAUNCH\${BrandShortName}.lnk" "$INSTDIR\${FileMainEXE}"
+  ${If} ${FileExists} "$QUICKLAUNCH\${BrandShortName}.lnk"
+    ShellLink::SetShortCutWorkingDirectory "$QUICKLAUNCH\${BrandShortName}.lnk" \
+                                           "$INSTDIR"
+  ${EndIf}
+FunctionEnd
+
 Function CheckExistingInstall
   ; If there is a pending file copy from a previous upgrade don't allow
   ; installing until after the system has rebooted.
@@ -1667,15 +1715,55 @@ Function preSummary
     DeleteINIStr "$PLUGINSDIR\summary.ini" "Settings" NextButtonText
   ${EndIf}
 
+
+  ; Remove the "Field 4" ini section in case the user hits back and changes the
+  ; installation directory which could change whether the make default checkbox
+  ; should be displayed.
+  DeleteINISec "$PLUGINSDIR\summary.ini" "Field 4"
+
+  ; Check if it is possible to write to HKLM
+  ClearErrors
+  WriteRegStr HKLM "Software\Mozilla" "${BrandShortName}InstallerTest" "Write Test"
+  ${Unless} ${Errors}
+    DeleteRegValue HKLM "Software\Mozilla" "${BrandShortName}InstallerTest"
+    ; Check if Firefox is the http handler for this user.
+    SetShellVarContext current ; Set SHCTX to the current user
+    ${IsHandlerForInstallDir} "http" $R9
+    ; If Firefox isn't the http handler for this user show the option to set
+    ; Firefox as the default browser.
+    ${If} "$R9" != "true"
+    ${AndIf} ${AtMostWin2008R2}
+      WriteINIStr "$PLUGINSDIR\summary.ini" "Settings" NumFields "4"
+      WriteINIStr "$PLUGINSDIR\summary.ini" "Field 4" Type   "checkbox"
+      WriteINIStr "$PLUGINSDIR\summary.ini" "Field 4" Text   "$(SUMMARY_TAKE_DEFAULTS)"
+      WriteINIStr "$PLUGINSDIR\summary.ini" "Field 4" Left   "0"
+      WriteINIStr "$PLUGINSDIR\summary.ini" "Field 4" Right  "-1"
+      WriteINIStr "$PLUGINSDIR\summary.ini" "Field 4" State  "1"
+      WriteINIStr "$PLUGINSDIR\summary.ini" "Field 4" Top    "32"
+      WriteINIStr "$PLUGINSDIR\summary.ini" "Field 4" Bottom "53"
+    ${EndIf}
+  ${EndUnless}
+
   ${If} "$TmpVal" == "true"
-    WriteINIStr "$PLUGINSDIR\summary.ini" "Settings" NumFields "4"
-
-    WriteINIStr "$PLUGINSDIR\summary.ini" "Field 4" Type   "label"
-    WriteINIStr "$PLUGINSDIR\summary.ini" "Field 4" Text   "$(SUMMARY_REBOOT_REQUIRED_INSTALL)"
-    WriteINIStr "$PLUGINSDIR\summary.ini" "Field 4" Left   "0"
-    WriteINIStr "$PLUGINSDIR\summary.ini" "Field 4" Right  "-1"
-    WriteINIStr "$PLUGINSDIR\summary.ini" "Field 4" Top    "35"
-    WriteINIStr "$PLUGINSDIR\summary.ini" "Field 4" Bottom "50"
+    ; If there is already a Type entry in the "Field 4" section with a value of
+    ; checkbox then the set as the default browser checkbox is displayed and
+    ; this text must be moved below it.
+    ReadINIStr $0 "$PLUGINSDIR\summary.ini" "Field 4" "Type"
+    ${If} "$0" == "checkbox"
+      StrCpy $0 "5"
+      WriteINIStr "$PLUGINSDIR\summary.ini" "Field $0" Top    "53"
+      WriteINIStr "$PLUGINSDIR\summary.ini" "Field $0" Bottom "68"
+    ${Else}
+      StrCpy $0 "4"
+      WriteINIStr "$PLUGINSDIR\summary.ini" "Field $0" Top    "35"
+      WriteINIStr "$PLUGINSDIR\summary.ini" "Field $0" Bottom "50"
+    ${EndIf}
+    WriteINIStr "$PLUGINSDIR\summary.ini" "Settings" NumFields "$0"
+
+    WriteINIStr "$PLUGINSDIR\summary.ini" "Field $0" Type   "label"
+    WriteINIStr "$PLUGINSDIR\summary.ini" "Field $0" Text   "$(SUMMARY_REBOOT_REQUIRED_INSTALL)"
+    WriteINIStr "$PLUGINSDIR\summary.ini" "Field $0" Left   "0"
+    WriteINIStr "$PLUGINSDIR\summary.ini" "Field $0" Right  "-1"
   ${EndIf}
 
   !insertmacro MUI_HEADER_TEXT "$(SUMMARY_PAGE_TITLE)" "$(SUMMARY_PAGE_SUBTITLE)"
diff --git a/browser/installer/windows/nsis/maintenanceservice_installer.nsi b/browser/installer/windows/nsis/maintenanceservice_installer.nsi
index c285e45bbdada..8683e5c8e45f2 100644
--- a/browser/installer/windows/nsis/maintenanceservice_installer.nsi
+++ b/browser/installer/windows/nsis/maintenanceservice_installer.nsi
@@ -118,7 +118,7 @@ Function .onInit
 
   SetSilent silent
 
-  ${Unless} ${AtLeastWin10}
+  ${Unless} ${AtLeastWin95}
     Abort
   ${EndUnless}
 FunctionEnd
diff --git a/browser/installer/windows/nsis/shared.nsh b/browser/installer/windows/nsis/shared.nsh
index 97b69f04dd48a..d9f7bfd7d8421 100755
--- a/browser/installer/windows/nsis/shared.nsh
+++ b/browser/installer/windows/nsis/shared.nsh
@@ -42,17 +42,33 @@
     ${EndIf}
   ${EndIf}
 
+  ; Adds a pinned Task Bar shortcut (see MigrateTaskBarShortcut for details).
+  ; When we enabled this feature for Windows 10 & 11 we decided _not_ to pin
+  ; during an update (even once) because we already offered to do when the
+  ; the user originally installed, and we don't want to go against their
+  ; explicit wishes.
+  ; For Windows 7 and 8, we've been doing this ~forever, and those users may
+  ; not have experienced the onboarding offer to pin to taskbar, so we're
+  ; leaving it enabled there.
+  ${If} ${AtMostWin2012R2}
+    ${MigrateTaskBarShortcut} "$AddTaskbarSC"
+  ${EndIf}
+
   ; Update the name/icon/AppModelID of our shortcuts as needed, then update the
   ; lastwritetime of the Start Menu shortcut to clear the tile icon cache.
   ; Do this for both shell contexts in case the user has shortcuts in multiple
   ; locations, then restore the previous context at the end.
   SetShellVarContext all
   ${UpdateShortcutsBranding}
-  ${TouchStartMenuShortcut}
+  ${If} ${AtLeastWin8}
+    ${TouchStartMenuShortcut}
+  ${EndIf}
   Call FixShortcutAppModelIDs
   SetShellVarContext current
   ${UpdateShortcutsBranding}
-  ${TouchStartMenuShortcut}
+  ${If} ${AtLeastWin8}
+    ${TouchStartMenuShortcut}
+  ${EndIf}
   Call FixShortcutAppModelIDs
   ${If} $TmpVal == "HKLM"
     SetShellVarContext all
@@ -103,13 +119,15 @@
   ; Record the Windows Error Reporting module
   WriteRegDWORD HKLM "SOFTWARE\Microsoft\Windows\Windows Error Reporting\RuntimeExceptionHelperModules" "$INSTDIR\mozwer.dll" 0
 
-  ; Apply LPAC permissions to install directory.
-  Push "Marker"
-  AccessControl::GrantOnFile \
-    "$INSTDIR" "(${LpacFirefoxInstallFilesSid})" "GenericRead + GenericExecute"
-  Pop $TmpVal ; get "Marker" or error msg
-  ${If} $TmpVal != "Marker"
-    Pop $TmpVal ; get "Marker"
+  ${If} ${AtLeastWin10}
+    ; Apply LPAC permissions to install directory.
+    Push "Marker"
+    AccessControl::GrantOnFile \
+      "$INSTDIR" "(${LpacFirefoxInstallFilesSid})" "GenericRead + GenericExecute"
+    Pop $TmpVal ; get "Marker" or error msg
+    ${If} $TmpVal != "Marker"
+      Pop $TmpVal ; get "Marker"
+    ${EndIf}
   ${EndIf}
 
 !ifdef MOZ_MAINTENANCE_SERVICE
@@ -161,7 +179,9 @@
   ${ResetLauncherProcessDefaults}
 !endif
 
-  ${WriteToastNotificationRegistration} $TmpVal
+  ${If} ${AtLeastWin10}
+    ${WriteToastNotificationRegistration} $TmpVal
+  ${EndIf}
 
 ; Make sure the scheduled task registration for the default browser agent gets
 ; updated, but only if we're not the instance of PostUpdate that was started
@@ -237,7 +257,9 @@ ${RemoveDefaultBrowserAgentShortcut}
     StrCpy $R1 "Software\Clients\StartMenuInternet\$0\InstallInfo"
   ${EndIf}
   WriteRegDWORD HKLM "$R1" "IconsVisible" 0
-  WriteRegDWORD HKCU "$R1" "IconsVisible" 0
+  ${If} ${AtLeastWin8}
+    WriteRegDWORD HKCU "$R1" "IconsVisible" 0
+  ${EndIf}
 
   SetShellVarContext all  ; Set $DESKTOP to All Users
   ${Unless} ${FileExists} "$DESKTOP\${BrandShortName}.lnk"
@@ -302,14 +324,17 @@ ${RemoveDefaultBrowserAgentShortcut}
     StrCpy $R1 "Software\Clients\StartMenuInternet\$0\InstallInfo"
   ${EndIf}
   WriteRegDWORD HKLM "$R1" "IconsVisible" 1
-  WriteRegDWORD HKCU "$R1" "IconsVisible" 1
+  ${If} ${AtLeastWin8}
+    WriteRegDWORD HKCU "$R1" "IconsVisible" 1
+  ${EndIf}
 
   SetShellVarContext all  ; Set $DESKTOP to All Users
   ${Unless} ${FileExists} "$DESKTOP\${BrandShortName}.lnk"
     CreateShortCut "$DESKTOP\${BrandShortName}.lnk" "$INSTDIR\${FileMainEXE}"
     ${If} ${FileExists} "$DESKTOP\${BrandShortName}.lnk"
       ShellLink::SetShortCutWorkingDirectory "$DESKTOP\${BrandShortName}.lnk" "$INSTDIR"
-      ${If} "$AppUserModelID" != ""
+      ${If} ${AtLeastWin7}
+      ${AndIf} "$AppUserModelID" != ""
         ApplicationID::Set "$DESKTOP\${BrandShortName}.lnk" "$AppUserModelID" "true"
       ${EndIf}
     ${Else}
@@ -319,7 +344,8 @@ ${RemoveDefaultBrowserAgentShortcut}
         ${If} ${FileExists} "$DESKTOP\${BrandShortName}.lnk"
           ShellLink::SetShortCutWorkingDirectory "$DESKTOP\${BrandShortName}.lnk" \
                                                  "$INSTDIR"
-          ${If} "$AppUserModelID" != ""
+          ${If} ${AtLeastWin7}
+          ${AndIf} "$AppUserModelID" != ""
             ApplicationID::Set "$DESKTOP\${BrandShortName}.lnk" "$AppUserModelID" "true"
           ${EndIf}
         ${EndIf}
@@ -333,7 +359,8 @@ ${RemoveDefaultBrowserAgentShortcut}
     ${If} ${FileExists} "$SMPROGRAMS\${BrandShortName}.lnk"
       ShellLink::SetShortCutWorkingDirectory "$SMPROGRAMS\${BrandShortName}.lnk" \
                                              "$INSTDIR"
-      ${If} "$AppUserModelID" != ""
+      ${If} ${AtLeastWin7}
+      ${AndIf} "$AppUserModelID" != ""
         ApplicationID::Set "$SMPROGRAMS\${BrandShortName}.lnk" "$AppUserModelID" "true"
       ${EndIf}
     ${Else}
@@ -344,13 +371,25 @@ ${RemoveDefaultBrowserAgentShortcut}
         ${If} ${FileExists} "$SMPROGRAMS\${BrandShortName}.lnk"
           ShellLink::SetShortCutWorkingDirectory "$SMPROGRAMS\${BrandShortName}.lnk" \
                                                  "$INSTDIR"
-          ${If} "$AppUserModelID" != ""
+          ${If} ${AtLeastWin7}
+          ${AndIf} "$AppUserModelID" != ""
             ApplicationID::Set "$SMPROGRAMS\${BrandShortName}.lnk" "$AppUserModelID" "true"
           ${EndIf}
         ${EndIf}
       ${EndUnless}
     ${EndIf}
   ${EndUnless}
+
+  ; Windows 7 doesn't use the QuickLaunch directory
+  ${Unless} ${AtLeastWin7}
+  ${AndUnless} ${FileExists} "$QUICKLAUNCH\${BrandShortName}.lnk"
+    CreateShortCut "$QUICKLAUNCH\${BrandShortName}.lnk" \
+                   "$INSTDIR\${FileMainEXE}"
+    ${If} ${FileExists} "$QUICKLAUNCH\${BrandShortName}.lnk"
+      ShellLink::SetShortCutWorkingDirectory "$QUICKLAUNCH\${BrandShortName}.lnk" \
+                                             "$INSTDIR"
+    ${EndIf}
+  ${EndUnless}
 !macroend
 !define ShowShortcuts "!insertmacro ShowShortcuts"
 
@@ -1255,8 +1294,10 @@ ${RemoveDefaultBrowserAgentShortcut}
       WriteRegDWORD HKCU \
         "Software\Mozilla\${AppName}\Installer\$AppUserModelID" \
         "WasPinnedToTaskbar" 1
-      ${If} "${SHOULD_PIN}" == "1"
-        ${PinToTaskBar}
+      ${If} ${AtLeastWin7}
+        ${If} "${SHOULD_PIN}" == "1"
+          ${PinToTaskBar}
+        ${EndIf}
       ${EndIf}
     ${EndIf}
   ${EndIf}
@@ -1445,8 +1486,79 @@ ${RemoveDefaultBrowserAgentShortcut}
           SetShellVarContext current ; Set SHCTX to the current user
         ${Else}
           SetShellVarContext all ; Set SHCTX to all users
-        ${EndIf}
-      ${EndUnless}
+          ${Unless} ${FileExists} "$SMPROGRAMS\$1"
+            SetShellVarContext current ; Set SHCTX to the current user
+            ${Unless} ${FileExists} "$SMPROGRAMS\$1"
+              StrCpy $8 "true"
+              CreateShortCut "$SMPROGRAMS\$1" "$INSTDIR\${FileMainEXE}"
+              ${If} ${FileExists} "$SMPROGRAMS\$1"
+                ShellLink::SetShortCutWorkingDirectory "$SMPROGRAMS\$1" \
+                                                       "$INSTDIR"
+                ${If} "$AppUserModelID" != ""
+                  ApplicationID::Set "$SMPROGRAMS\$1" "$AppUserModelID" "true"
+                ${EndIf}
+              ${EndIf}
+            ${EndUnless}
+          ${EndUnless}
+
+          ${If} ${FileExists} "$SMPROGRAMS\$1"
+            ; Count of Start Menu pinned shortcuts before unpinning.
+            ${PinnedToStartMenuLnkCount} $R9
+
+            ; Having multiple shortcuts pointing to different installations with
+            ; the same AppUserModelID (e.g. side by side installations of the
+            ; same version) will make the TaskBar shortcut's lists into an bad
+            ; state where the lists are not shown. To prevent this first
+            ; uninstall the pinned item.
+            ApplicationID::UninstallPinnedItem "$SMPROGRAMS\$1"
+
+            ; Count of Start Menu pinned shortcuts after unpinning.
+            ${PinnedToStartMenuLnkCount} $R8
+
+            ; If there is a change in the number of Start Menu pinned shortcuts
+            ; assume that unpinning unpinned a side by side installation from
+            ; the Start Menu and pin this installation to the Start Menu.
+            ${Unless} $R8 == $R9
+              ; Pin the shortcut to the Start Menu. 5381 is the shell32.dll
+              ; resource id for the "Pin to Start Menu" string.
+              InvokeShellVerb::DoIt "$SMPROGRAMS" "$1" "5381"
+            ${EndUnless}
+
+            ${If} ${AtMostWin2012R2}
+              ; Pin the shortcut to the TaskBar. 5386 is the shell32.dll
+              ; resource id for the "Pin to Taskbar" string.
+              InvokeShellVerb::DoIt "$SMPROGRAMS" "$1" "5386"
+            ${ElseIf} ${AtMostWaaS} 1809
+              ; In Windows 10 the "Pin to Taskbar" resource was removed, so we
+              ; can't access the verb that way anymore. We have a create a
+              ; command key using the GUID that's assigned to this action and
+              ; then invoke that as a verb. This works up until build 1809
+              ReadRegStr $R9 HKLM \
+                "Software\Microsoft\Windows\CurrentVersion\Explorer\CommandStore\shell\Windows.taskbarpin" \
+                "ExplorerCommandHandler"
+              WriteRegStr HKCU "Software\Classes\*\shell\${AppRegName}-$AppUserModelID" "ExplorerCommandHandler" $R9
+              InvokeShellVerb::DoIt "$SMPROGRAMS" "$1" "${AppRegName}-$AppUserModelID"
+              DeleteRegKey HKCU "Software\Classes\*\shell\${AppRegName}-$AppUserModelID"
+            ${Else}
+              ; In the Windows 10 1903 and up (and Windows 11) the above no
+              ; longer works. We have yet another method for these versions
+              ; which is detailed in the PinToTaskbar plugin code.
+              PinToTaskbar::Pin "$SMPROGRAMS\$1"
+            ${EndIf}
+
+            ; Delete the shortcut if it was created
+            ${If} "$8" == "true"
+              Delete "$SMPROGRAMS\$1"
+            ${EndIf}
+          ${EndIf}
+
+          ${If} $TmpVal == "HKCU"
+            SetShellVarContext current ; Set SHCTX to the current user
+          ${Else}
+            SetShellVarContext all ; Set SHCTX to all users
+          ${EndIf}
+        ${EndUnless}
+      ${EndIf}
     ${EndIf}
   ${EndIf}
 !macroend
@@ -1613,6 +1725,7 @@ Function SetAsDefaultAppUserHKCU
   ClearErrors
   ReadRegStr $0 HKCU "Software\Clients\StartMenuInternet\$R9\DefaultIcon" ""
   ${If} ${Errors}
+  ${OrIf} ${AtMostWin2008R2}
     ClearErrors
     ReadRegStr $0 HKLM "Software\Clients\StartMenuInternet\$R9\DefaultIcon" ""
   ${EndIf}
@@ -1629,6 +1742,7 @@ Function SetAsDefaultAppUserHKCU
   ClearErrors
   ReadRegStr $0 HKCU "Software\Clients\StartMenuInternet\$R9\DefaultIcon" ""
   ${If} ${Errors}
+  ${OrIf} ${AtMostWin2008R2}
     ClearErrors
     ReadRegStr $0 HKLM "Software\Clients\StartMenuInternet\$R9\DefaultIcon" ""
   ${EndIf}
@@ -1638,12 +1752,16 @@ Function SetAsDefaultAppUserHKCU
     ${If} ${FileExists} "$0"
       ${GetLongPath} "$0" $0
       ${If} "$0" == "$INSTDIR"
-        ; This function cannot do anything to actually set the default browser,
-        ; it can only set up the registry entries to allow the user to do so.
-        ; Getting here means that those entries already exist for this
-        ; installation, we just found them, so there is nothing more to be
-        ; done.
-        Return
+        ; On Windows >= 8, this function cannot do anything to actually set
+        ; the default browser, it can only set up the registry entries to
+        ; allow the user to do so. Getting here means that those entries already
+        ; exist for this installation, we just found them, so there is nothing
+        ; more to be done.
+        ${If} ${AtLeastWin8}
+          Return
+        ${Else}
+          WriteRegStr HKCU "Software\Clients\StartMenuInternet" "" "$R9"
+        ${EndIf}
       ${EndIf}
     ${EndIf}
   ${EndUnless}
@@ -1653,9 +1771,11 @@ Function SetAsDefaultAppUserHKCU
   ; It's unlikely that we didn't find a StartMenuInternet key above, but it is
   ; possible; it likely would mean this copy of the application was extracted
   ; directly from a ZIP file and the installer was never run.
-  ${SetStartMenuInternet} "HKCU"
-  ${FixShellIconHandler} "HKCU"
-  ${FixClassKeys} ; Does not use SHCTX
+  ${If} ${AtLeastWin8}
+    ${SetStartMenuInternet} "HKCU"
+    ${FixShellIconHandler} "HKCU"
+    ${FixClassKeys} ; Does not use SHCTX
+  ${EndIf}
 
   ${SetHandlers}
 
@@ -1693,7 +1813,8 @@ FunctionEnd
 
 ; Helper for updating the shortcut application model IDs.
 Function FixShortcutAppModelIDs
-  ${If} "$AppUserModelID" != ""
+  ${If} ${AtLeastWin7}
+  ${AndIf} "$AppUserModelID" != ""
     ${UpdateShortcutAppModelIDs} "$INSTDIR\${FileMainEXE}" "$AppUserModelID" $0
   ${EndIf}
 FunctionEnd
@@ -1717,18 +1838,89 @@ Function SetAsDefaultAppUser
   ; MigrateTaskBarShortcut will not see the value of AddTaskbarSC, so we
   ; send it via a register instead.
   StrCpy $R0 $AddTaskbarSC
-  ; We want to avoid having a UAC prompt since we'll already have another
-  ; action for control panel default browser selection popping upto the user.
-  ; The start menu keys can be added into HKCU.  The call to
-  ; SetAsDefaultAppUserHKCU will have already set the HKCU keys for
-  ; SetStartMenuInternet.
-  ; Check if this is running in an elevated process
+  ; On Win8, we want to avoid having a UAC prompt since we'll already have
+  ; another action for control panel default browser selection popping up
+  ; to the user.  Win8 is the first OS where the start menu keys can be
+  ; added into HKCU.  The call to SetAsDefaultAppUserHKCU will have already
+  ; set the HKCU keys for SetStartMenuInternet.
+  ${If} ${AtLeastWin8}
+    ; Check if this is running in an elevated process
+    ClearErrors
+    ${GetParameters} $0
+    ${GetOptions} "$0" "/UAC:" $0
+    ${If} ${Errors} ; Not elevated
+      Call SetAsDefaultAppUserHKCU
+    ${Else} ; Elevated - execute the function in the unelevated process
+      GetFunctionAddress $0 SetAsDefaultAppUserHKCU
+      UAC::ExecCodeSegment $0
+    ${EndIf}
+    Return ; Nothing more needs to be done
+  ${EndIf}
+
+  ; Before Win8, it is only possible to set this installation of the application
+  ; as the StartMenuInternet handler if it was added to the HKLM
+  ; StartMenuInternet registry keys.
+  ; http://support.microsoft.com/kb/297878
+
+  ; Check if this install location registered as a StartMenuInternet client
+  ClearErrors
+  ReadRegStr $0 HKCU "Software\Clients\StartMenuInternet\${AppRegName}-$AppUserModelID\DefaultIcon" ""
+  ${If} ${Errors}
+  ${OrIf} ${AtMostWin2008R2}
+    ClearErrors
+    ReadRegStr $0 HKLM "Software\Clients\StartMenuInternet\${AppRegName}-$AppUserModelID\DefaultIcon" ""
+  ${EndIf}
+  ${If} ${Errors}
+    ${StrFilter} "${FileMainEXE}" "+" "" "" $R9
+    ClearErrors
+    ReadRegStr $0 HKCU "Software\Clients\StartMenuInternet\$R9\DefaultIcon" ""
+    ${If} ${Errors}
+    ${OrIf} ${AtMostWin2008R2}
+      ClearErrors
+      ReadRegStr $0 HKLM "Software\Clients\StartMenuInternet\$R9\DefaultIcon" ""
+    ${EndIf}
+  ${EndIf}
+
+  ${Unless} ${Errors}
+    ${GetPathFromString} "$0" $0
+    ${GetParent} "$0" $0
+    ${If} ${FileExists} "$0"
+      ${GetLongPath} "$0" $0
+      ${If} "$0" == "$INSTDIR"
+        ; Check if this is running in an elevated process
+        ClearErrors
+        ${GetParameters} $0
+        ${GetOptions} "$0" "/UAC:" $0
+        ${If} ${Errors} ; Not elevated
+          Call SetAsDefaultAppUserHKCU
+        ${Else} ; Elevated - execute the function in the unelevated process
+          GetFunctionAddress $0 SetAsDefaultAppUserHKCU
+          UAC::ExecCodeSegment $0
+        ${EndIf}
+        Return ; Nothing more needs to be done
+      ${EndIf}
+    ${EndIf}
+  ${EndUnless}
+
+  ; The code after ElevateUAC won't be executed when the user:
+  ; a) is a member of the administrators group (e.g. elevation is required)
+  ; b) is not a member of the administrators group and chooses to elevate
+  ${ElevateUAC}
+
+  ${SetStartMenuInternet} "HKLM"
+
+  SetShellVarContext all  ; Set SHCTX to all users (e.g. HKLM)
+
+  ${FixClassKeys} ; Does not use SHCTX
+  ${FixShellIconHandler} "HKLM"
+  ${RemoveDeprecatedKeys} ; Does not use SHCTX
+
   ClearErrors
   ${GetParameters} $0
   ${GetOptions} "$0" "/UAC:" $0
-  ${If} ${Errors} ; Not elevated
+  ${If} ${Errors}
     Call SetAsDefaultAppUserHKCU
-  ${Else} ; Elevated - execute the function in the unelevated process
+  ${Else}
     GetFunctionAddress $0 SetAsDefaultAppUserHKCU
     UAC::ExecCodeSegment $0
   ${EndIf}
diff --git a/browser/installer/windows/nsis/stub.nsi b/browser/installer/windows/nsis/stub.nsi
index 7173c8b6decc3..331b91895625a 100644
--- a/browser/installer/windows/nsis/stub.nsi
+++ b/browser/installer/windows/nsis/stub.nsi
@@ -24,6 +24,7 @@ ManifestDPIAware true
 
 !addplugindir ./
 
+Var CheckboxSetAsDefault
 Var CheckboxShortcuts
 Var CheckboxSendPing
 Var CheckboxInstallMaintSvc
@@ -40,6 +41,7 @@ Var ExistingTopDir
 Var SpaceAvailableBytes
 Var InitialInstallDir
 Var HandleDownload
+Var CanSetAsDefault
 Var InstallCounterStep
 Var InstallTotalSteps
 Var ProgressCompleted
@@ -350,6 +352,21 @@ Function .onInit
   ; Used to determine if the default installation directory was used.
   StrCpy $InitialInstallDir "$INSTDIR"
 
+  ClearErrors
+  WriteRegStr HKLM "Software\Mozilla" "${BrandShortName}InstallerTest" \
+                   "Write Test"
+
+  ; Only display set as default when there is write access to HKLM and on Win7
+  ; and below.
+  ${If} ${Errors}
+  ${OrIf} ${AtLeastWin8}
+    StrCpy $CanSetAsDefault "false"
+  ${Else}
+    DeleteRegValue HKLM "Software\Mozilla" "${BrandShortName}InstallerTest"
+    StrCpy $CanSetAsDefault "true"
+  ${EndIf}
+  StrCpy $CheckboxSetAsDefault "0"
+
   ; Initialize the majority of variables except those that need to be reset
   ; when a page is displayed.
   StrCpy $ExitCode "${ERR_DOWNLOAD_CANCEL}"
@@ -890,6 +907,8 @@ Function LaunchFullInstaller
   ; install in case it needs to perform operations that the stub doesn't
   ; know about.
   WriteINIStr "$PLUGINSDIR\${CONFIG_INI}" "Install" "InstallDirectoryPath" "$INSTDIR"
+  ; Don't create the QuickLaunch or Taskbar shortcut from the launched installer
+  WriteINIStr "$PLUGINSDIR\${CONFIG_INI}" "Install" "QuickLaunchShortcut" "false"
 
   ; Always create a start menu shortcut, so the user always has some way
   ; to access the application.
@@ -1108,7 +1127,19 @@ Function SendPing
       ${EndIf}
     ${EndIf}
 
-    StrCpy $R3 "1"
+    ${If} $CanSetAsDefault == "true"
+      ${If} $CheckboxSetAsDefault == "1"
+        StrCpy $R3 "2"
+      ${Else}
+        StrCpy $R3 "3"
+      ${EndIf}
+    ${Else}
+      ${If} ${AtLeastWin8}
+        StrCpy $R3 "1"
+      ${Else}
+        StrCpy $R3 "0"
+      ${EndIf}
+    ${EndIf}
 
 !ifdef STUB_DEBUG
     MessageBox MB_OK "${BaseURLStubPing} \
diff --git a/browser/installer/windows/nsis/uninstaller.nsi b/browser/installer/windows/nsis/uninstaller.nsi
index 695beed25f25e..49e63d101c46c 100755
--- a/browser/installer/windows/nsis/uninstaller.nsi
+++ b/browser/installer/windows/nsis/uninstaller.nsi
@@ -501,8 +501,10 @@ Section "Uninstall"
   ${un.DeleteShortcuts}
 
   ${If} "$AppUserModelID" != ""
-    ; Unregister resources associated with taskbar jump lists.
-    ApplicationID::UninstallJumpLists "$AppUserModelID"
+    ; Unregister resources associated with Win7 taskbar jump lists.
+    ${If} ${AtLeastWin7}
+      ApplicationID::UninstallJumpLists "$AppUserModelID"
+    ${EndIf}
     ; Remove the update sync manager's multi-instance lock file
     Call un.GetCommonDirectory
     Pop $0
@@ -510,7 +512,9 @@ Section "Uninstall"
   ${EndIf}
 
   ${If} "$AppUserModelIDPrivate" != ""
-    ApplicationID::UninstallJumpLists "$AppUserModelIDPrivate"
+    ${If} ${AtLeastWin7}
+      ApplicationID::UninstallJumpLists "$AppUserModelIDPrivate"
+    ${EndIf}
   ${EndIf}
 
   ; Clean up old maintenance service logs
@@ -675,37 +679,39 @@ Section "Uninstall"
 !endif
 
   ; Remove Toast Notification registration.
-  ; Find any GUID used for this installation.
-  ClearErrors
-  ReadRegStr $0 HKLM "Software\Classes\AppUserModelId\${ToastAumidPrefix}$AppUserModelID" "CustomActivator"
-
-  DeleteRegValue HKLM "Software\Classes\AppUserModelId\${ToastAumidPrefix}$AppUserModelID" "CustomActivator"
-  DeleteRegValue HKLM "Software\Classes\AppUserModelId\${ToastAumidPrefix}$AppUserModelID" "DisplayName"
-  DeleteRegValue HKLM "Software\Classes\AppUserModelId\${ToastAumidPrefix}$AppUserModelID" "IconUri"
-  DeleteRegKey HKLM "Software\Classes\AppUserModelId\${ToastAumidPrefix}$AppUserModelID"
-  ${If} "$0" != ""
-    DeleteRegValue HKLM "Software\Classes\AppID\$0" "DllSurrogate"
-    DeleteRegKey HKLM "Software\Classes\AppID\$0"
-    DeleteRegValue HKLM "Software\Classes\CLSID\$0" "AppID"
-    DeleteRegValue HKLM "Software\Classes\CLSID\$0\InProcServer32" ""
-    DeleteRegKey HKLM "Software\Classes\CLSID\$0\InProcServer32"
-    DeleteRegKey HKLM "Software\Classes\CLSID\$0"
-  ${EndIf}
+  ${If} ${AtLeastWin10}
+    ; Find any GUID used for this installation.
+    ClearErrors
+    ReadRegStr $0 HKLM "Software\Classes\AppUserModelId\${ToastAumidPrefix}$AppUserModelID" "CustomActivator"
+
+    DeleteRegValue HKLM "Software\Classes\AppUserModelId\${ToastAumidPrefix}$AppUserModelID" "CustomActivator"
+    DeleteRegValue HKLM "Software\Classes\AppUserModelId\${ToastAumidPrefix}$AppUserModelID" "DisplayName"
+    DeleteRegValue HKLM "Software\Classes\AppUserModelId\${ToastAumidPrefix}$AppUserModelID" "IconUri"
+    DeleteRegKey HKLM "Software\Classes\AppUserModelId\${ToastAumidPrefix}$AppUserModelID"
+    ${If} "$0" != ""
+      DeleteRegValue HKLM "Software\Classes\AppID\$0" "DllSurrogate"
+      DeleteRegKey HKLM "Software\Classes\AppID\$0"
+      DeleteRegValue HKLM "Software\Classes\CLSID\$0" "AppID"
+      DeleteRegValue HKLM "Software\Classes\CLSID\$0\InProcServer32" ""
+      DeleteRegKey HKLM "Software\Classes\CLSID\$0\InProcServer32"
+      DeleteRegKey HKLM "Software\Classes\CLSID\$0"
+    ${EndIf}
 
-  ClearErrors
-  ReadRegStr $0 HKCU "Software\Classes\AppUserModelId\${ToastAumidPrefix}$AppUserModelID" "CustomActivator"
-
-  DeleteRegValue HKCU "Software\Classes\AppUserModelId\${ToastAumidPrefix}$AppUserModelID" "CustomActivator"
-  DeleteRegValue HKCU "Software\Classes\AppUserModelId\${ToastAumidPrefix}$AppUserModelID" "DisplayName"
-  DeleteRegValue HKCU "Software\Classes\AppUserModelId\${ToastAumidPrefix}$AppUserModelID" "IconUri"
-  DeleteRegKey HKCU "Software\Classes\AppUserModelId\${ToastAumidPrefix}$AppUserModelID"
-  ${If} "$0" != ""
-    DeleteRegValue HKCU "Software\Classes\AppID\$0" "DllSurrogate"
-    DeleteRegKey HKCU "Software\Classes\AppID\$0"
-    DeleteRegValue HKCU "Software\Classes\CLSID\$0" "AppID"
-    DeleteRegValue HKCU "Software\Classes\CLSID\$0\InProcServer32" ""
-    DeleteRegKey HKCU "Software\Classes\CLSID\$0\InProcServer32"
-    DeleteRegKey HKCU "Software\Classes\CLSID\$0"
+    ClearErrors
+    ReadRegStr $0 HKCU "Software\Classes\AppUserModelId\${ToastAumidPrefix}$AppUserModelID" "CustomActivator"
+
+    DeleteRegValue HKCU "Software\Classes\AppUserModelId\${ToastAumidPrefix}$AppUserModelID" "CustomActivator"
+    DeleteRegValue HKCU "Software\Classes\AppUserModelId\${ToastAumidPrefix}$AppUserModelID" "DisplayName"
+    DeleteRegValue HKCU "Software\Classes\AppUserModelId\${ToastAumidPrefix}$AppUserModelID" "IconUri"
+    DeleteRegKey HKCU "Software\Classes\AppUserModelId\${ToastAumidPrefix}$AppUserModelID"
+    ${If} "$0" != ""
+      DeleteRegValue HKCU "Software\Classes\AppID\$0" "DllSurrogate"
+      DeleteRegKey HKCU "Software\Classes\AppID\$0"
+      DeleteRegValue HKCU "Software\Classes\CLSID\$0" "AppID"
+      DeleteRegValue HKCU "Software\Classes\CLSID\$0\InProcServer32" ""
+      DeleteRegKey HKCU "Software\Classes\CLSID\$0\InProcServer32"
+      DeleteRegKey HKCU "Software\Classes\CLSID\$0"
+    ${EndIf}
   ${EndIf}
 
   ${un.RemovePrecompleteEntries} "false"
@@ -1162,10 +1168,15 @@ Function un.onGUIEnd
     ; If we were the default browser and we've now been uninstalled, we need
     ; to take steps to make sure the user doesn't see an "open with" dialog;
     ; they're helping us out by answering this survey, they don't need more
-    ; friction.
+    ; friction. Sometimes Windows 7 and 8 automatically switch the default to
+    ; IE, but it isn't reliable, so we'll manually invoke IE in that case.
     ; Windows 10 always seems to just clear the default browser, so for it
     ; we'll manually invoke Edge using Edge's custom URI scheme.
-    ExecInExplorer::Exec "microsoft-edge:$R1"
+    ${If} ${AtLeastWin10}
+      ExecInExplorer::Exec "microsoft-edge:$R1"
+    ${Else}
+      ExecInExplorer::Exec "iexplore.exe" /cmdargs "$R1"
+    ${EndIf}
   ${EndIf}
 
   ; Finally send the ping, there's no GUI to freeze in case it is slow.
diff --git a/browser/locales/en-US/installer/custom.properties b/browser/locales/en-US/installer/custom.properties
index be816b870de1a..30d430a75639d 100644
--- a/browser/locales/en-US/installer/custom.properties
+++ b/browser/locales/en-US/installer/custom.properties
@@ -38,6 +38,7 @@ SUMMARY_PAGE_SUBTITLE=Ready to start installing $BrandShortName
 SUMMARY_INSTALLED_TO=$BrandShortName will be installed to the following location:
 SUMMARY_REBOOT_REQUIRED_INSTALL=A restart of your computer may be required to complete the installation.
 SUMMARY_REBOOT_REQUIRED_UNINSTALL=A restart of your computer may be required to complete the uninstall.
+SUMMARY_TAKE_DEFAULTS=U&se $BrandShortName as my default web browser
 SUMMARY_INSTALL_CLICK=Click Install to continue.
 SUMMARY_UPGRADE_CLICK=Click Upgrade to continue.
 SURVEY_TEXT=&Tell us what you thought of $BrandShortName
@@ -90,4 +91,6 @@ OPTION_CUSTOM_RADIO=&Custom
 
 # LOCALIZATION NOTE:
 # The following text replaces the Install button text on the summary page.
+# Verify that the access key for InstallBtn (in override.properties) and
+# UPGRADE_BUTTON is not already used by SUMMARY_TAKE_DEFAULTS.
 UPGRADE_BUTTON=&Upgrade
diff --git a/toolkit/mozapps/installer/windows/nsis/common.nsh b/toolkit/mozapps/installer/windows/nsis/common.nsh
index 533e9a83bbfee..0df17d1f8a2f1 100755
--- a/toolkit/mozapps/installer/windows/nsis/common.nsh
+++ b/toolkit/mozapps/installer/windows/nsis/common.nsh
@@ -3953,59 +3953,61 @@
       ; We call ApplicationID::UninstallPinnedItem once per shortcut here
       ; (and explicitly not in DeleteShortcutsFromLog). Calling it again later
       ; would remove the association of side by side installations.
-      ; Since shortcuts that are pinned can later be removed without removing
-      ; the pinned shortcut unpin the pinned shortcuts for the application's
-      ; main exe using the pinned shortcuts themselves.
-      StrCpy $R7 "$QUICKLAUNCH\User Pinned"
-
-      ${If} ${FileExists} "$R7\TaskBar"
-        ; Delete TaskBar pinned shortcuts for the application's main exe
-        FindFirst $R6 $R8 "$R7\TaskBar\*.lnk"
-        ${Do}
-          ${If} ${FileExists} "$R7\TaskBar\$R8"
-            ShellLink::GetShortCutTarget "$R7\TaskBar\$R8"
-            Pop $R5
-            ${${_MOZFUNC_UN}GetLongPath} "$R5" $R5
-            ShellLink::GetShortCutWorkingDirectory "$SMPROGRAMS\$R8"
-            Pop $R4
-            ${If} "$R5" == "$INSTDIR\${FileMainEXE}"
-            ${OrIf} "$R4" == "$INSTDIR"
-              ApplicationID::UninstallPinnedItem "$R7\TaskBar\$R8"
+      ${If} ${AtLeastWin7}
+        ; Since shortcuts that are pinned can later be removed without removing
+        ; the pinned shortcut unpin the pinned shortcuts for the application's
+        ; main exe using the pinned shortcuts themselves.
+        StrCpy $R7 "$QUICKLAUNCH\User Pinned"
+
+        ${If} ${FileExists} "$R7\TaskBar"
+          ; Delete TaskBar pinned shortcuts for the application's main exe
+          FindFirst $R6 $R8 "$R7\TaskBar\*.lnk"
+          ${Do}
+            ${If} ${FileExists} "$R7\TaskBar\$R8"
+              ShellLink::GetShortCutTarget "$R7\TaskBar\$R8"
               Pop $R5
+              ${${_MOZFUNC_UN}GetLongPath} "$R5" $R5
+              ShellLink::GetShortCutWorkingDirectory "$SMPROGRAMS\$R8"
+              Pop $R4
+              ${If} "$R5" == "$INSTDIR\${FileMainEXE}"
+              ${OrIf} "$R4" == "$INSTDIR"
+                ApplicationID::UninstallPinnedItem "$R7\TaskBar\$R8"
+                Pop $R5
+              ${EndIf}
             ${EndIf}
-          ${EndIf}
-          ClearErrors
-          FindNext $R6 $R8
-          ${If} ${Errors}
-            ${ExitDo}
-          ${EndIf}
-        ${Loop}
-        FindClose $R6
-      ${EndIf}
+            ClearErrors
+            FindNext $R6 $R8
+            ${If} ${Errors}
+              ${ExitDo}
+            ${EndIf}
+          ${Loop}
+          FindClose $R6
+        ${EndIf}
 
-      ${If} ${FileExists} "$R7\StartMenu"
-        ; Delete Start Menu pinned shortcuts for the application's main exe
-        FindFirst $R6 $R8 "$R7\StartMenu\*.lnk"
-        ${Do}
-          ${If} ${FileExists} "$R7\StartMenu\$R8"
-            ShellLink::GetShortCutTarget "$R7\StartMenu\$R8"
-            Pop $R5
-            ${${_MOZFUNC_UN}GetLongPath} "$R5" $R5
-            ShellLink::GetShortCutWorkingDirectory "$SMPROGRAMS\$R8"
-            Pop $R4
-            ${If} "$R5" == "$INSTDIR\${FileMainEXE}"
-            ${OrIf} "$R4" == "$INSTDIR"
-                ApplicationID::UninstallPinnedItem "$R7\StartMenu\$R8"
-                Pop $R5
+        ${If} ${FileExists} "$R7\StartMenu"
+          ; Delete Start Menu pinned shortcuts for the application's main exe
+          FindFirst $R6 $R8 "$R7\StartMenu\*.lnk"
+          ${Do}
+            ${If} ${FileExists} "$R7\StartMenu\$R8"
+              ShellLink::GetShortCutTarget "$R7\StartMenu\$R8"
+              Pop $R5
+              ${${_MOZFUNC_UN}GetLongPath} "$R5" $R5
+              ShellLink::GetShortCutWorkingDirectory "$SMPROGRAMS\$R8"
+              Pop $R4
+              ${If} "$R5" == "$INSTDIR\${FileMainEXE}"
+              ${OrIf} "$R4" == "$INSTDIR"
+                  ApplicationID::UninstallPinnedItem "$R7\StartMenu\$R8"
+                  Pop $R5
+              ${EndIf}
             ${EndIf}
-          ${EndIf}
-          ClearErrors
-          FindNext $R6 $R8
-          ${If} ${Errors}
-            ${ExitDo}
-          ${EndIf}
-        ${Loop}
-        FindClose $R6
+            ClearErrors
+            FindNext $R6 $R8
+            ${If} ${Errors}
+              ${ExitDo}
+            ${EndIf}
+          ${Loop}
+          FindClose $R6
+        ${EndIf}
       ${EndIf}
 
       ${${_MOZFUNC_UN}GetLongPath} "$INSTDIR\uninstall\${SHORTCUTS_LOG}" $R9
@@ -5438,6 +5440,13 @@
               ${EndIf}
             ${EndIf}
 
+            ReadINIStr $R8 $R7 "Install" "QuickLaunchShortcut"
+            ${If} $R8 == "false"
+              StrCpy $AddQuickLaunchSC "0"
+            ${Else}
+              StrCpy $AddQuickLaunchSC "1"
+            ${EndIf}
+
             ReadINIStr $R8 $R7 "Install" "DesktopShortcut"
             ${If} $R8 == "false"
               StrCpy $AddDesktopSC "0"
@@ -5529,6 +5538,7 @@
           ${EndIf}
         ${EndIf}
 
+        ${InstallGetOption} $R8 "QuickLaunchShortcut" $AddQuickLaunchSC
         ${InstallGetOption} $R8 "DesktopShortcut" $AddDesktopSC
         ${InstallGetOption} $R8 "StartMenuShortcuts" $AddStartMenuSC
         ; We still accept the plural version for backwards compatibility,
@@ -6557,7 +6567,13 @@
       ${LogMsg} "App Version: $R8"
       ${LogMsg} "GRE Version: $R9"
 
-      ${If} ${IsWin10}
+      ${If} ${IsWin7}
+        ${LogMsg} "OS Name    : Windows 7"
+      ${ElseIf} ${IsWin8}
+        ${LogMsg} "OS Name    : Windows 8"
+      ${ElseIf} ${IsWin8.1}
+        ${LogMsg} "OS Name    : Windows 8.1"
+      ${ElseIf} ${IsWin10}
         ${LogMsg} "OS Name    : Windows 10"
       ${ElseIf} ${AtLeastWin10}
         ${LogMsg} "OS Name    : Above Windows 10"
@@ -7164,7 +7180,8 @@
 
       StrCpy $R5 "false"
 
-      ${If} ${FileExists} "$QUICKLAUNCH\User Pinned\TaskBar"
+      ${If} ${AtLeastWin7}
+      ${AndIf} ${FileExists} "$QUICKLAUNCH\User Pinned\TaskBar"
         FindFirst $R8 $R7 "$QUICKLAUNCH\User Pinned\TaskBar\*.lnk"
         ${Do}
           ${If} ${FileExists} "$QUICKLAUNCH\User Pinned\TaskBar\$R7"
@@ -7243,7 +7260,8 @@
 
       StrCpy $R5 "false"
 
-      ${If} ${FileExists} "$QUICKLAUNCH\User Pinned\StartMenu"
+      ${If} ${AtLeastWin7}
+      ${AndIf} ${FileExists} "$QUICKLAUNCH\User Pinned\StartMenu"
         FindFirst $R8 $R7 "$QUICKLAUNCH\User Pinned\StartMenu\*.lnk"
         ${Do}
           ${If} ${FileExists} "$QUICKLAUNCH\User Pinned\StartMenu\$R7"
@@ -7314,7 +7332,8 @@
 
       StrCpy $R9 0
 
-      ${If} ${FileExists} "$QUICKLAUNCH\User Pinned\TaskBar"
+      ${If} ${AtLeastWin7}
+      ${AndIf} ${FileExists} "$QUICKLAUNCH\User Pinned\TaskBar"
         FindFirst $R8 $R7 "$QUICKLAUNCH\User Pinned\TaskBar\*.lnk"
         ${Do}
           ${If} ${FileExists} "$QUICKLAUNCH\User Pinned\TaskBar\$R7"
@@ -7374,7 +7393,8 @@
 
       StrCpy $R9 0
 
-      ${If} ${FileExists} "$QUICKLAUNCH\User Pinned\StartMenu"
+      ${If} ${AtLeastWin7}
+      ${AndIf} ${FileExists} "$QUICKLAUNCH\User Pinned\StartMenu"
         FindFirst $R8 $R7 "$QUICKLAUNCH\User Pinned\StartMenu\*.lnk"
         ${Do}
           ${If} ${FileExists} "$QUICKLAUNCH\User Pinned\StartMenu\$R7"
@@ -7454,129 +7474,131 @@
 
       StrCpy $R3 "false"
 
-      ; installed shortcuts
-      ${${_MOZFUNC_UN}GetLongPath} "$INSTDIR\uninstall\${SHORTCUTS_LOG}" $R6
-      ${If} ${FileExists} "$R6"
-        ; Update the Start Menu shortcuts' App ID for this application
-        StrCpy $R2 -1
-        ${Do}
-          IntOp $R2 $R2 + 1 ; Increment the counter
-          ClearErrors
-          ReadINIStr $R5 "$R6" "STARTMENU" "Shortcut$R2"
-          ${If} ${Errors}
-            ${ExitDo}
-          ${EndIf}
+      ${If} ${AtLeastWin7}
+        ; installed shortcuts
+        ${${_MOZFUNC_UN}GetLongPath} "$INSTDIR\uninstall\${SHORTCUTS_LOG}" $R6
+        ${If} ${FileExists} "$R6"
+          ; Update the Start Menu shortcuts' App ID for this application
+          StrCpy $R2 -1
+          ${Do}
+            IntOp $R2 $R2 + 1 ; Increment the counter
+            ClearErrors
+            ReadINIStr $R5 "$R6" "STARTMENU" "Shortcut$R2"
+            ${If} ${Errors}
+              ${ExitDo}
+            ${EndIf}
 
-          ${If} ${FileExists} "$SMPROGRAMS\$R5"
-            ShellLink::GetShortCutTarget "$SMPROGRAMS\$$R5"
-            Pop $R4
-            ${GetLongPath} "$R4" $R4
-            ${If} "$R4" == "$R9" ; link path == install path
-              ApplicationID::Set "$SMPROGRAMS\$R5" "$R8" "true"
+            ${If} ${FileExists} "$SMPROGRAMS\$R5"
+              ShellLink::GetShortCutTarget "$SMPROGRAMS\$$R5"
               Pop $R4
+              ${GetLongPath} "$R4" $R4
+              ${If} "$R4" == "$R9" ; link path == install path
+                ApplicationID::Set "$SMPROGRAMS\$R5" "$R8" "true"
+                Pop $R4
+              ${EndIf}
             ${EndIf}
-          ${EndIf}
-        ${Loop}
+          ${Loop}
 
-        ; Update the Quick Launch shortcuts' App ID for this application
-        StrCpy $R2 -1
-        ${Do}
-          IntOp $R2 $R2 + 1 ; Increment the counter
-          ClearErrors
-          ReadINIStr $R5 "$R6" "QUICKLAUNCH" "Shortcut$R2"
-          ${If} ${Errors}
-            ${ExitDo}
-          ${EndIf}
+          ; Update the Quick Launch shortcuts' App ID for this application
+          StrCpy $R2 -1
+          ${Do}
+            IntOp $R2 $R2 + 1 ; Increment the counter
+            ClearErrors
+            ReadINIStr $R5 "$R6" "QUICKLAUNCH" "Shortcut$R2"
+            ${If} ${Errors}
+              ${ExitDo}
+            ${EndIf}
 
-          ${If} ${FileExists} "$QUICKLAUNCH\$R5"
-            ShellLink::GetShortCutTarget "$QUICKLAUNCH\$R5"
-            Pop $R4
-            ${GetLongPath} "$R4" $R4
-            ${If} "$R4" == "$R9" ; link path == install path
-              ApplicationID::Set "$QUICKLAUNCH\$R5" "$R8" "true"
+            ${If} ${FileExists} "$QUICKLAUNCH\$R5"
+              ShellLink::GetShortCutTarget "$QUICKLAUNCH\$R5"
               Pop $R4
+              ${GetLongPath} "$R4" $R4
+              ${If} "$R4" == "$R9" ; link path == install path
+                ApplicationID::Set "$QUICKLAUNCH\$R5" "$R8" "true"
+                Pop $R4
+              ${EndIf}
             ${EndIf}
-          ${EndIf}
-        ${Loop}
+          ${Loop}
 
-        ; Update the Start Menu Programs shortcuts' App ID for this application
-        ClearErrors
-        ReadINIStr $R7 "$R6" "SMPROGRAMS" "RelativePathToDir"
-        ${Unless} ${Errors}
-          ${${_MOZFUNC_UN}GetLongPath} "$SMPROGRAMS\$R7" $R7
-          ${Unless} "$R7" == ""
-            StrCpy $R2 -1
-            ${Do}
-              IntOp $R2 $R2 + 1 ; Increment the counter
-              ClearErrors
-              ReadINIStr $R5 "$R6" "SMPROGRAMS" "Shortcut$R2"
-              ${If} ${Errors}
-                ${ExitDo}
-              ${EndIf}
+          ; Update the Start Menu Programs shortcuts' App ID for this application
+          ClearErrors
+          ReadINIStr $R7 "$R6" "SMPROGRAMS" "RelativePathToDir"
+          ${Unless} ${Errors}
+            ${${_MOZFUNC_UN}GetLongPath} "$SMPROGRAMS\$R7" $R7
+            ${Unless} "$R7" == ""
+              StrCpy $R2 -1
+              ${Do}
+                IntOp $R2 $R2 + 1 ; Increment the counter
+                ClearErrors
+                ReadINIStr $R5 "$R6" "SMPROGRAMS" "Shortcut$R2"
+                ${If} ${Errors}
+                  ${ExitDo}
+                ${EndIf}
 
-              ${If} ${FileExists} "$R7\$R5"
-                ShellLink::GetShortCutTarget "$R7\$R5"
-                Pop $R4
-                ${GetLongPath} "$R4" $R4
-                ${If} "$R4" == "$R9" ; link path == install path
-                  ApplicationID::Set "$R7\$R5" "$R8" "true"
+                ${If} ${FileExists} "$R7\$R5"
+                  ShellLink::GetShortCutTarget "$R7\$R5"
                   Pop $R4
+                  ${GetLongPath} "$R4" $R4
+                  ${If} "$R4" == "$R9" ; link path == install path
+                    ApplicationID::Set "$R7\$R5" "$R8" "true"
+                    Pop $R4
+                  ${EndIf}
                 ${EndIf}
-              ${EndIf}
-            ${Loop}
+              ${Loop}
+            ${EndUnless}
           ${EndUnless}
-        ${EndUnless}
-      ${EndIf}
+        ${EndIf}
 
-      StrCpy $R7 "$QUICKLAUNCH\User Pinned"
-      StrCpy $R3 "false"
+        StrCpy $R7 "$QUICKLAUNCH\User Pinned"
+        StrCpy $R3 "false"
 
-      ; $R9 = main application executable path
-      ; $R8 = appid
-      ; $R7 = user pinned path
-      ; $R6 = find handle
-      ; $R5 = found filename
-      ; $R4 = GetShortCutTarget result
+        ; $R9 = main application executable path
+        ; $R8 = appid
+        ; $R7 = user pinned path
+        ; $R6 = find handle
+        ; $R5 = found filename
+        ; $R4 = GetShortCutTarget result
 
-      ; TaskBar links
-      FindFirst $R6 $R5 "$R7\TaskBar\*.lnk"
-      ${Do}
-        ${If} ${FileExists} "$R7\TaskBar\$R5"
-          ShellLink::GetShortCutTarget "$R7\TaskBar\$R5"
-          Pop $R4
-          ${If} "$R4" == "$R9" ; link path == install path
-            ApplicationID::Set "$R7\TaskBar\$R5" "$R8" "true"
-            Pop $R4 ; pop Set result off the stack
-            StrCpy $R3 "true"
+        ; TaskBar links
+        FindFirst $R6 $R5 "$R7\TaskBar\*.lnk"
+        ${Do}
+          ${If} ${FileExists} "$R7\TaskBar\$R5"
+            ShellLink::GetShortCutTarget "$R7\TaskBar\$R5"
+            Pop $R4
+            ${If} "$R4" == "$R9" ; link path == install path
+              ApplicationID::Set "$R7\TaskBar\$R5" "$R8" "true"
+              Pop $R4 ; pop Set result off the stack
+              StrCpy $R3 "true"
+            ${EndIf}
           ${EndIf}
-        ${EndIf}
-        ClearErrors
-        FindNext $R6 $R5
-        ${If} ${Errors}
-          ${ExitDo}
-        ${EndIf}
-      ${Loop}
-      FindClose $R6
+          ClearErrors
+          FindNext $R6 $R5
+          ${If} ${Errors}
+            ${ExitDo}
+          ${EndIf}
+        ${Loop}
+        FindClose $R6
 
-      ; Start menu links
-      FindFirst $R6 $R5 "$R7\StartMenu\*.lnk"
-      ${Do}
-        ${If} ${FileExists} "$R7\StartMenu\$R5"
-          ShellLink::GetShortCutTarget "$R7\StartMenu\$R5"
-          Pop $R4
-          ${If} "$R4" == "$R9" ; link path == install path
-            ApplicationID::Set "$R7\StartMenu\$R5" "$R8" "true"
-            Pop $R4 ; pop Set result off the stack
-            StrCpy $R3 "true"
+        ; Start menu links
+        FindFirst $R6 $R5 "$R7\StartMenu\*.lnk"
+        ${Do}
+          ${If} ${FileExists} "$R7\StartMenu\$R5"
+            ShellLink::GetShortCutTarget "$R7\StartMenu\$R5"
+            Pop $R4
+            ${If} "$R4" == "$R9" ; link path == install path
+              ApplicationID::Set "$R7\StartMenu\$R5" "$R8" "true"
+              Pop $R4 ; pop Set result off the stack
+              StrCpy $R3 "true"
+            ${EndIf}
           ${EndIf}
-        ${EndIf}
-        ClearErrors
-        FindNext $R6 $R5
-        ${If} ${Errors}
-          ${ExitDo}
-        ${EndIf}
-      ${Loop}
-      FindClose $R6
+          ClearErrors
+          FindNext $R6 $R5
+          ${If} ${Errors}
+            ${ExitDo}
+          ${EndIf}
+        ${Loop}
+        FindClose $R6
+      ${EndIf}
 
       ClearErrors
 
@@ -7690,21 +7712,23 @@
       Exch $R8 ; stack: $R8, $R9   | $R8 = regpath
       Push $R7
 
-      ${${_MOZFUNC_UN}GetLongPath} "$R9" $R9
-      ; Always create a new AppUserModelID and overwrite the existing one
-      ; for the current installation path.
-      CityHash::GetCityHash64 "$R9"
-      Pop $AppUserModelID
-      ${If} $AppUserModelID == "error"
-        GoTo end
-      ${EndIf}
-      ClearErrors
-      WriteRegStr HKLM "$R8" "$R9" "$AppUserModelID"
-      ${If} ${Errors}
+      ${If} ${AtLeastWin7}
+        ${${_MOZFUNC_UN}GetLongPath} "$R9" $R9
+        ; Always create a new AppUserModelID and overwrite the existing one
+        ; for the current installation path.
+        CityHash::GetCityHash64 "$R9"
+        Pop $AppUserModelID
+        ${If} $AppUserModelID == "error"
+          GoTo end
+        ${EndIf}
         ClearErrors
-        WriteRegStr HKCU "$R8" "$R9" "$AppUserModelID"
+        WriteRegStr HKLM "$R8" "$R9" "$AppUserModelID"
         ${If} ${Errors}
-          StrCpy $AppUserModelID "error"
+          ClearErrors
+          WriteRegStr HKCU "$R8" "$R9" "$AppUserModelID"
+          ${If} ${Errors}
+            StrCpy $AppUserModelID "error"
+          ${EndIf}
         ${EndIf}
       ${EndIf}
 
@@ -7874,12 +7898,15 @@
       StrCpy $ITaskbarList3 0
       ; Don't create when running silently.
       ${Unless} ${Silent}
-        System::Call "ole32::CoCreateInstance(g '${CLSID_ITaskbarList}', \
-                                              i 0, \
-                                              i ${CLSCTX_INPROC_SERVER}, \
-                                              g '${IID_ITaskbarList3}', \
-                                              *i .s)"
-        Pop $ITaskbarList3
+        ; This is only supported on Win 7 and above.
+        ${If} ${AtLeastWin7}
+          System::Call "ole32::CoCreateInstance(g '${CLSID_ITaskbarList}', \
+                                                i 0, \
+                                                i ${CLSCTX_INPROC_SERVER}, \
+                                                g '${IID_ITaskbarList3}', \
+                                                *i .s)"
+          Pop $ITaskbarList3
+        ${EndIf}
       ${EndUnless}
     FunctionEnd