Which version of Win7 are your running?
Did you upgrade
the ATI drivers to 9.7 from a previous version?
If so, did you cleanup the previous version install using Driver Cleaner Pro and/or CCleaner?
If not that may be the problem and the solution. Uninstall ATI drivers, clean out old installations, re-install.
Driver Cleaner Professional download from Guru3D.com
CCleaner - Home