Add another to the list of people having problems. I'm running an ASUS P5-E Mobo and a GeForce 8600 GTS. While I don't get a black screen or anything, my video and picture resolution is rather poor on Windows 7 with no explanation. Same video/picture looks perfect in XP, but on Windows 7 it looks grainy. I've tried all different types of codec packs, players, you name it. Some people have reported downgrading the graphics
drivers to solve the problem but I've yet to see this.
It's really amazing how common this problem is with the particular GeForce cards and how there is still no answer as to what's causing it. I've made several threads to no avail.