You should be able to use the Vista x64 drivers
, the drivers for your card can be found here: ATI Catalystâ„¢ Legacy Display Driver
The specific download you likely want is the full Catalyst Suite
To install them under Windows 7, you will need to run them under 'Compatibility' mode. To do that, right-click on the installer, select the 'Compatibility
' tab and select the Compatibility Mode and select 'Vista SP1
Next, select 'Run as Admin
' at the bottom with the checkbox.