atomicWAR :
could be drivers for your video card....but it could be a hardware fault as well (mob, graphics, ram, etc) try doing a clean install of drivers in safe mode. (hit f8 prior to windows splash screen)
go to device manager and uninstall the graphics card...be sure to check delete driver box then reinstall drivers and reboot and see if it fixs things. let me know if not i have more ideas.
Hmmmmm, I did try to use my old nvidia geforce 8400 gs with my system, before I used that card this problem did not arise... I did uninstall the driver after I deemed the card was not speedy enough to my liking.
Looking at device manager I only see intel hd graphics adapter, no nvidia, so I cannot uninstall any driver bits that might possibly have been left behind if that is what is causing this. Do I need to insert the nvidia card back in?