Index: /trunk/src/VBox/Additions/WINNT/Graphics/Video/mp/common/VBoxMPVidModes.cpp
===================================================================
--- /trunk/src/VBox/Additions/WINNT/Graphics/Video/mp/common/VBoxMPVidModes.cpp	(revision 50861)
+++ /trunk/src/VBox/Additions/WINNT/Graphics/Video/mp/common/VBoxMPVidModes.cpp	(revision 50862)
@@ -494,9 +494,7 @@
 #ifdef VBOX_XPDM_MINIPORT
     return (pExt->CurrentMode == 0);
-#elif defined(VBOX_WDDM_WIN8)
-    return FALSE;
-#else /* VBOX_WDDM_MINIPORT && !VBOX_WDDM_MINIPORT */
-    return (!VBoxCommonFromDeviceExt(pExt)->cDisplays
-            || !pExt->aSources[iDisplay].pPrimaryAllocation);
+#else
+    VBOXWDDM_SOURCE *pSource = &pExt->aSources[iDisplay];
+    return !pSource->AllocData.SurfDesc.width || !pSource->AllocData.SurfDesc.height;
 #endif
 }