[DXG] Define GUIDs only once

win32ss/reactx/dxg/dxg_int.h

@@ -19,7 +19,6 @@
 #include <wingdi.h>
 #include <winddi.h>
 #include <ddkernel.h>
-#include <initguid.h>
 #include <ddrawi.h>
 #include <ntgdityp.h>
 #include <psfuncs.h>

win32ss/reactx/dxg/main.c

@@ -8,6 +8,20 @@
  *       15/10-2007   Magnus Olsen
  */
 
+#include <ntifs.h>
+
+/* Win32 Headers */
+#define WINBASEAPI
+#define STARTF_USESIZE 2
+#define STARTF_USEPOSITION 4
+#define INTERNAL_CALL NTAPI
+#define NT_BUILD_ENVIRONMENT
+
+#include <windef.h>
+#include <winerror.h>
+#include <wingdi.h>
+#include <winddi.h>
+#include <initguid.h>
 #include <dxg_int.h>
 #include "dxg_driver.h"