And would you happen to be using windows 8?
if so it`s not just you, its a common problem with the Ati graphics driver and windows 8.
If your using an old driver or a new one. try another driver, or version number of it from the Amd website, and ati driver support section.
Make sure you uninstall all the old Ati drivers first.
use the geek3d driver sweeper for ati cards to clean out all ati drivers from here, install and run and select ati brand in tab.
then install different ati drivers or a new one depending on your card model.
It should fix the problem you are having ok.
http://www.geeks3d.com/20080616/guru3d-driversweeper/