ATI have released new Vista Compatible drivers for their range of Radeon graphics cards. However, ATI have been bought out by AMD and the drivers are located on the new AMD website.
To download the correct drivers for your ATI graphics card, visit the AMD website here:
Then, select the appropriate version of Windows Vista that you need drivers for (most users will be using 32-Bit versions of Vista). Proceed to select the graphics card family and model to be directed to the final download page.
The instructions and options for graphics card drivers will be presented on this final page, but we recommend you download the full Catalyst software suite (unless you know you don't need these extra features).