I'm running Windows 8.1 currently, has worked fine for the time I've had it but want to go back to Vista (Just ran good on my system). I tried to boot the .iso from BIOS when I restarted but had an issue. Ever since I did that my screen has been blurry and on 800x600 resolution. Tried updating the drivers, but didn't change it. How do I get it back to how it was before??