First I go, C:/ATI/setup. Go through that till you get to uninstall, it'll want you to reboot so do it, then log back in and run Driversweeper from Windows, then reboot again. Finally on entering Windows again start the new installer for the new driver- done. Never had any problems this way. When I install it for a second the screen goes black which is when it's enabling Crossfire, so when I finish installing the driver Crossfire is already enabled. You may need to enable Crossfire before you uninstall (also Cat AI 'advanced' aswell) if you haven't already, and also another thing is when I had my 3850s I used 2 bridges instead of 1. Hope that helps.