Only 3 FPS on Mac mini, boot camp, windows 7 Using the GPU test tool from FurMark i get only 3 FPS. 

In normal use I notice it when playing fullscreen videos: When the video pans horizontal i get these stripes across the picture.

My setup is like this:

Mac mini 2011 2.3GHz dual-core Intel Core i5/ 2 GB DDR3 SDRAM (PC3-10600)/500 GB HD/Intel HD 3000/Thunderbolt
OS: windows 7
Tv: Panasonic G10 50" plasma
Tv and computer are connected with an 2 meter HDMI cable

I've tried to change the HDMI cable - did not change anything.

What can I try?
Finally! - I worked out what the problem was. 

I had followed the speedup-tip:


  Head to the Control Panel's Performance Information and Tools section, and choose Adjust  Visual Effects. Here you'll find a long list of effects, but simply choosing "Adjust for  best performance" will turn everything off. You'll feel like you stepped back into a decade ago.