Here's a thing to try: Copy and paste the following lines in Notepad and save as something like "devices.bat" - you can either use the quotes without altering anything or change the file type setting from .txt to all filetypes and remove the quotes. If you do it right, you should get an executable batch file as a result. Right click it and choose "run as administrator". Your Device Manager should open. In the View menu choose "show hidden devices". Navigate to "display adapters", click the + sign to open it and simply delete any instance of your old video cards. Leave the standard VGA! You can go through other instances too, you might find traces of your old antivirus programs which you should also get rid of, not to mention a multitude of disk drives and storage controllers left by each and every memory stick you've ever used. Basically everything greyed is safe to remove, but under "non plug and play drivers" there's some item's I'd rather leave be like Fs_Rec and RDPNP as well as under and "sound, video and game controllers" where I'd only touch items clearly related to AMD/ATi, everything else being original Windows files. Also delete anything with a ! sign inside a yellow triangle, hopefully they'd get corrected during the next boot. If your Windows isn't badly corrupted, any mistakenly deleted item should reinstall automatically, so it's relatively safe.
@echo off
devmgr_show_nonpresent_device s=1
start devmgmt.msc
Speaking about a reinstall, the advice MrRipley gave isn't quite correct, IMO. If you do as he advised, you'd get a "Windows OLD" folder containing almost everything form your current install, but no programs inside it will work. As he said, you'd have to reinstall every program you need. Your personal files would be there fully usable, though. There's another way to refresh Windows Vista or 7 which will save everything! The trick is to start the installing from within Windows. Put the installation disk into the optical drive and follow the instructions. You'd want to "install windows" and in the following screen choose "upgrade" instead of "clean". If you boot from the DVD the upgrade option would be greyed, so you'll have to start inside your current Windows. N.B. your DVD has to be of the same version as the Windows in your computer. So if your DVD doesn't include any Service Pack, you'd have to uninstall those first from the computer to get to the same level. They can be uninstalled through Windows Update, IIRC, from View Update History. Only the SP's have to be removed, smaller updates won't matter.
Speaking about the logic... It sounds funny, but Windows really can be "upgraded" to the same version it already is. The result will be similar to that of the "Repair install" feature of XP, only made somewhat more confusing to use.
