Add ZoomIt conflict warning to Settings

src/modules/ZoomIt/ZoomIt/Zoomit.cpp

@@ -6938,6 +6938,12 @@ int APIENTRY wWinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance
 		CreateEvent( NULL, FALSE, FALSE, _T("ZoomitActive"));
 	}	
 	if( GetLastError() == ERROR_ALREADY_EXISTS ) {
+		if (g_StartedByPowerToys)
+		{
+			MessageBox(NULL, L"We've detected another instance of ZoomIt is already running.\nCan't start a new ZoomIt instance from PowerToys.",
+			APPNAME, MB_ICONERROR);
+			return 1;
+		}
 
 		// Tell the other instance to show the options dialog
 		g_hWndMain = FindWindow( L"ZoomitClass", NULL );

src/settings-ui/Settings.UI/SettingsXAML/Views/ZoomItPage.xaml

@@ -34,6 +34,12 @@
                     IsOpen="{x:Bind ViewModel.IsEnabledGpoConfigured, Mode=OneWay}"
                     IsTabStop="{x:Bind ViewModel.IsEnabledGpoConfigured, Mode=OneWay}"
                     Severity="Informational" />
+                <InfoBar
+                    x:Uid="ZoomIt_SimultaneousStandaloneZoomItWarning"
+                    IsClosable="False"
+                    IsOpen="True"
+                    IsTabStop="True"
+                    Severity="Informational" />
                 <controls:SettingsGroup x:Uid="ZoomIt_BehaviorGroup" IsEnabled="{x:Bind ViewModel.IsEnabled, Mode=OneWay}">
                     <tkcontrols:SettingsCard x:Uid="ZoomIt_Toggle_ShowTrayIcon">
                         <ToggleSwitch x:Uid="ToggleSwitch" IsOn="{x:Bind ViewModel.ShowTrayIcon, Mode=TwoWay}" />

src/settings-ui/Settings.UI/Strings/en-us/Resources.resw

@@ -4484,6 +4484,9 @@ Activate by holding the key for the character you want to add an accent to, then
     <value>Learn more about ZoomIt</value>
     <comment>{Locked="ZoomIt"}</comment>
   </data>
+  <data name="ZoomIt_SimultaneousStandaloneZoomItWarning.Title" xml:space="preserve">
+    <value>Running ZoomIt through PowerToys and the classical standalone ZoomIt executable at the same time is not supported. Please exit the original ZoomIt before enabling it here.</value>
+  </data>
   <data name="ZoomIt_BehaviorGroup.Header" xml:space="preserve">
     <value>Behavior</value>
   </data>