Red-Checkered design appearing on screen for Windows 7, why?

[umbralsoul]

On several occasions now I've had a red-checkered design appear on my screen, either on the top & bottom borders of the screen, or covering the screen entirely. I took the opportunity to take a screenshot on the last occurrence but the image only captured fragments of what I could actually see. ImageShack® - Online Photo and Video Hosting
Why is it occurring? How can I stop it?

[for whatever reason, the links do not wish to work. I think it works now.]

 

[d0m0]

Something wrong with your VGA probably. Try updating the drivers

 

[neo101]

After driver install

Try pushing card back into slot/push elec lead/s firmly socket
Try in other pc

Otherwise very often indicative of failing card (memory chip)

 

[alphanumeric]

If what you see on screen does not show up in a screen shot, that almost certainty means its a graphics card, monitor cable or monitor problem. The screen shot is based on the data sent to the video card, not on what the card sends out to the monitor. If your screen shot looks normal but your displayed image does not something is going wrong between the video card and the monitor. I'd reseat your video card and make sure your video cable is firmly connected at both ends.