Originally Posted By: Rand
open the case and see how full of dirt it is, and if all the fans are moving.
Yes, if the video card has a tiny fan they can often seize because of dirt or just being cheap, AMD had a problem where they designed the GPU with the fan pointing DOWNWARDS, which cause the bearings to fail prematurely on those cards..look at your card and see if the fan is pointing down.
That being said I would just try to reinstall the existing driver IF it was working perfectly previously. All you need to do is select uninstall driver, and then select "restart" when the PC boots it will reinstall the current driver for the video card.