You can always just get them straight from AMD, Asus is the worst for updating that sort of thing on their download pages (my board at least lists Windows 7
drivers, too bad they are more than a year old), even more so when you consider that your motherboard is more than compatible with Windows 7. You don't say whether 32 bit or 64 bit so,
32 bit -
Motherboard/ Integrated Video Drivers for Windows 7 32-Bit edition
64 bit -
Motherboard/ Integrated Video Drivers for Windows 7 64-Bit edition
The one you want is the South Bridge
Driver, and you will also need the AHCI or RAID driver depending on which you have your SATA ports configured as. You don't need wither of them if you have the ports configured to run in IDE mode.
Also seeing as you have an AMD video card you can also get them from the full catalyst Suite,
Downloads
when you install/update the video card drivers.