This is most likely a driver problem. There is not enough information about your system posted, so advising exactly what to do is impossible. I will try to present a high level view of what you need to do ( at least for Nvidia but the process will work the same for ATI).

If you are running Nvidia, simply reinstalling the driver will not work. If you recently upgraded from one driver version to another, you may be caught with mismatched driver versions, which will cause this problem. I have had this myself before. 2142 crashes can corrupt some video driver files, or if you run SLI mode, it can corrupt some of your SLI video drivers which will cause this problem. Reinstalling the driver will not fix this problem for various reasons. In either case, the only solution is to wipe them out and start over.

You will need to download a tool called driver sweeper to remove all the Nvidia left overs. You can get it from www.phyxion.net
I use version 1.5.5 and it works fine.

After you have uninstalled the Nvidia drivers from control panel, run driver sweeper Analyse and clean to remove the left over Nvidia drivers it finds. This will wipe out your Nvidia drivers completely. You can now start fresh.

If you run SLI, then you should download the latest nforce SLI/Video driver combo from Nvidia that matches your SLI chip type, or run it from the disk that came with your mobo. Install this combo only and run your system. The video driver is not necessarily the latest version but the 2 are designed to work together. If you have a driver issue ( rather then hardware ), this should clear up your problem.

If you don't run SLI, get the disc that came with your video card and reinstall the drivers from there. Yes they are older versions but you know it will work with your system. Install from the disc first. Afterwards, if you find your system is working properly, then you can look to upgrade the driver. The idea is to get your system back to a known working version of software before you do upgrades.