src/java.desktop/windows/native/libawt/java2d/d3d/D3DGraphicsDevice.cpp

@@ -176,11 +176,13 @@
     // use when creating the device
     pMgr->SetFSFocusWindow(adapter, hWnd);
 
     newParams = *pCurParams;
     newParams.hDeviceWindow = hWnd;
-    newParams.Windowed = FALSE;
+    // Since we are not creating hwnd with WS_EX_TOPMOST flag, so Windowed flag 
+    // needs to be TRUE for fullscreen window 
+    newParams.Windowed = TRUE;  
     newParams.BackBufferCount = 1;
     newParams.BackBufferFormat = dm.Format;
     newParams.FullScreen_RefreshRateInHz = dm.RefreshRate;
     newParams.BackBufferWidth = dm.Width;
     newParams.BackBufferHeight = dm.Height;