I'd go to Device Manager & revert video driver
by wpgwpg - 2/2/13 7:20 PM
It sounds like something happened to your video driver. I'd go to Device Manager and right-click the video driver, and have it revert to the previous one. Did you by chance opt to load a new one via Windows Update? That could explain what's happened because getting drivers from other than the manufacturer has been known to cause this kind of thing.