Frequently, the driver on the included CD is old and faulty.. Try visiting the Radeon site and find an updated driver for your card. I don't see that you've listed the operating system on your computer for which I could supply the newest driver, but you should be able to find it yourself at the link below:
Likewise, visiting the computer manufacturer's website might give you the option for updating your BIOS software/firmware as well.
Hope this helps.
My former graphics card (Geforce 8800GT) kicked the bucket so I got a new one, a Radeon HD 6850. Now after installation my computer has started freezing at random, forcing me to hard reset every time. Usually it happens on desktop or in the middle of a game, but sometimes the pc hangs at Windows boot screen and occasionally freezes on the BIOS control panel as well. And that's nuts.
I've tried switching the power supply (currently at 480W), switching RAM thinking it was faulty, and reinstalling the graphics card drivers. So far no good.
Could it be that my graphics card is faulty, or is the motherboard giving in? Remember, nothing was wrong until the new 6850! Please help!