I think I know ....
On the 26th Microsoft put out an update that made the Windows 7 desktop work like the Windows 8 desktop.
Basically, DWM always runs. It cannot be turned off now. Also, the whole display is rendered with DirectX.
I have been looking into this stuff because I use Fraps to record my desktop.. but that no longer works ![]()
See if anything here helps
http://msdn.microsoft.com/en-us/library/windows/desktop/aa969538(v=vs.85).aspx
good luck

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