Have you tried booting into safe mode and reinstalling the appropriate driver downloads from your laptop manufacturer?
The laptop should boot into safemode because Windows will utilize the Windows built-in display drivers such as utilized during an OS install. The video driver download from the manufacturer will likely be an executable containing that folder. Just install it as normal. Also, if the manufacturer has a separate download for the ATI Control Center (or something like that) make sure to install that as well.
I think that should fix the problem. Give it a shot.
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