You can get this straight from the AMD Drivers Website: AMD Graphics Drivers & Software
. You can choose your card and 32 or 64-bit OS. Note that what you will get is a Vista driver in the end as driver support for Radeon X1xxx cards and below was dropped with the last release being Catalyst 10.2 I believe, which was before Windows 7. The Vista driver I can confirm works successfully on Windows 7 without any issues.
Let us know how it turns out or if you get any errors.