I recently received a hand me down Radeon HD 6790 from my room mate. I removed my NVIDIA GT 8800 and did a clean install with Windows 7 Ultimate N. When it booted it had 9.x AMD drivers installed (What I assume are the base drivers). So I went ahead and tried to download the 13.1 drivers off the AMD website. However, my installations always fail.
I saw a potential fix for my problem, booting in safe mode and using driver fusion to delete old AMD drivers and reinstall my new ones after a reboot, but that did not work.