If you have been using an Intel X58 system running Windows 7 x32/x64, you might have experience this strange problem. The SiSoft Sandra 2010 Lite edition benchmark will fail when run after Catalyst 10.7 is installed onto the system. The problem can be replicated on X64 Win 7 too.
Uninstall the ATi Catalyst driver and use the system supplied ATi WDDM driver solved the problem. Post your experience in the forums.