Delete that C:\ATI you have now.
Use this. Extract it to C:\ATI RapidShare: 1-CLICK Web hosting - Easy Filehosting
Update the driver
by going to device manager, right click card, update driver, browse, let me pick, have disk, browse.
Now find CL_83742.inf in C:\ATI\Support\9-10_vista32_win7_32_dd_ccc_wdm_enu\Driver\Packages\Drivers
If it complains that it's unsigned, install anyway. Reboot. Choose an Aero theme by right clicking desktop, personalize.
Run setup.exe in C:\ATI\Support\9-10_vista32_win7_32_dd_ccc_wdm_enu\Driver
to get CCC installed.