I installed windows 7 and everything worked fine. Suddenly graphic acceleration appears to have been deactivated (although there are no such indications in the control panel of my nvidia graphic card).
The system has become very slow and the windows no longer slide into the taskbar, although many other graphics effects are still present (such as transparent windows and 3d task switch with windows+tab keys).
I suspect the for some reason windows has activated its WARP system and is now no longer using my GPU but is using my CPU for graphic acceleration.
Any suggestions what I can do?