I would check to see if your computer is running your graphics off the graphics card or the mother board. My nvidea gives me the option of running from the mainboard or the card.
The issue your having is related to your cpu. If you have overclocked it undo it. If you can check to see if your graphics card is running your graphics do it.
If your clear on both counts then I would suggest looking into your bios setting and seeing if your voltage settings match what your mainboard and cpu should be running. If not change them to match your hardware. If they are then a bios upgrade might be in order.
Here is a discussion that can lead you in a better direction
http://www.overclockers.com/forums/s...d.php?t=610441
