diff --git a/vrs/AsyncDiskFileChunk.hpp b/vrs/AsyncDiskFileChunk.hpp
index 6f03f8a7..b151692e 100644
--- a/vrs/AsyncDiskFileChunk.hpp
+++ b/vrs/AsyncDiskFileChunk.hpp
@@ -172,30 +172,30 @@ struct AsyncWindowsHandle {
       return readNotWrite ? DISKFILE_NOT_ENOUGH_DATA : DISKFILE_PARTIAL_WRITE_ERROR;
     }
 
-    OVERLAPPED ov;
-
-    ov.hEvent = 0;
+    // N.B. this does not create an hEvent for the OVERLAPPED structure, instead using the file
+    // handle. This is only a valid thing to do if there are NO other IO operations occuring during
+    // this one. The calls to flushWriteBuffer() before calling this ensures this is the case.
+    OVERLAPPED ov = {};
     ov.Offset = (DWORD)offset;
     ov.OffsetHigh = (DWORD)(offset >> 32);
 
+    DWORD dwNumberOfBytesTransferred = 0;
+    bool success = false;
     if (readNotWrite) {
-      if (ReadFile(h_, buf, dwToXfer, nullptr, &ov)) {
-        return SUCCESS;
-      }
+      success = ReadFile(h_, buf, dwToXfer, &dwNumberOfBytesTransferred, &ov);
     } else {
-      if (WriteFile(h_, buf, dwToXfer, nullptr, &ov)) {
-        return SUCCESS;
-      }
+      success = WriteFile(h_, buf, dwToXfer, &dwNumberOfBytesTransferred, &ov);
     }
 
-    int error = GetLastError();
-    if (error != ERROR_IO_PENDING) {
-      return error;
-    }
+    if (!success) {
+      int error = GetLastError();
+      if (error != ERROR_IO_PENDING) {
+        return error;
+      }
 
-    DWORD dwNumberOfBytesTransferred;
-    if (!GetOverlappedResult(h_, &ov, &dwNumberOfBytesTransferred, TRUE)) {
-      return GetLastError();
+      if (!GetOverlappedResult(h_, &ov, &dwNumberOfBytesTransferred, TRUE)) {
+        return GetLastError();
+      }
     }
 
     outSize = dwNumberOfBytesTransferred;
diff --git a/vrs/test/file_tests/DeviceSimulatorTest.cpp b/vrs/test/file_tests/DeviceSimulatorTest.cpp
index b99bc341..9091fb63 100644
--- a/vrs/test/file_tests/DeviceSimulatorTest.cpp
+++ b/vrs/test/file_tests/DeviceSimulatorTest.cpp
@@ -25,7 +25,6 @@
 
 #include <vrs/DiskFile.h>
 #include <vrs/RecordFileReader.h>
-#include <vrs/os/Platform.h>
 #include <vrs/os/Utils.h>
 
 #include <vrs/test/helpers/VRSTestsHelpers.h>
@@ -128,7 +127,6 @@ TEST_F(DeviceSimulator, multiThreadAsyncAioNotDirect) {
   deleteChunkedFile(testPath);
 }
 
-#if IS_VRS_FB_INTERNAL() || !IS_WINDOWS_PLATFORM() // avoid OSS/Windows
 TEST_F(DeviceSimulator, multiThreadAsyncSync) {
   const string testPath = os::getTempFolder() + "MultiThreadAsyncSync.vrs";
 
@@ -140,7 +138,6 @@ TEST_F(DeviceSimulator, multiThreadAsyncSync) {
 
   deleteChunkedFile(testPath);
 }
-#endif
 
 TEST_F(DeviceSimulator, multiThreadAsyncPsync) {
   const string testPath = os::getTempFolder() + "MultiThreadAsyncPsync.vrs";