For a few weeks now, my work system hasn't been able to properly install updated AMD drivers. It would seem that there's an issue with the installer conflicting with differing versions of the MFC framework on Windows: it doesn't always come up, but since I'm always trying different programs, I had at least 3 different versions of the same runtimes installed.
Source of this fix
1. Run the proper installer from AMD. Extract the files, then quit the installer.
2. Use an admin command prompt to go to the folder where the stuff was extracted (usually into a C:\ATI or C:\AMD folder). There will be a folder for the whole driver set, and two folders inside that: BIN and BIN64; pick the one you need for 32-bit or 64-bit use.
3. Run ATISetup.exe -Uninstall -output screen , then ATISetup.exe -Install -output screen
4. It doesn't say reboot, but I would suggest it. I noticed an immediate difference, even though my Windows graphics score dropped by .1