Didn't work. I tried installing the drivers manually through Device Manager, but when I boot into normal mode (not Safe mode), I get a solid blue screen (not a BSOD).
Edit: I later tried to install it through the command line (go to the /Bin64 folder in elevated cmd.exe, type atisetup.exe -install -output screen), but I got:
Detecting<.........
!!!Error code=99 Detection Manager: Failed to load the driver
..>
Error: Failed to find any installable components
Edit again: Also, I have VC++ 2008 alongside VC++ 2005. Could that be related to the problem?
Edit yet again: I replaced the 5800 series drivers in Device Manager with the Standard VGA ones. I then rebooted into normal mode, but into the Administrator account. I did the manual atisetup.exe method, and it seems to work with the drivers from the XFX disc.
Final (?) edit: The drivers installed, but I got the same solid color screen when I tried to log into my account (it was grey-black due to me having the Pinwheel Galaxy as a desktop image, I think). I restarted, then tried the Administrator account. That seemed to work (and 1680x1050 is back again). Only Administrator works. I get my desktop on my normal account for about a few seconds, then I get the solid grey screen.