Just got my new 3870 today. I immediately installed it in a system that already had a 2600 pro. The new card wasn't recognized. I then did my usual uninstall everything ATI and rebooted into safe mode and used Driver Cleaner.net to completely remove ATI software. I rebooted again and installed the latest drivers from the ATI website for my card. I keep getting a "SEVERE: Setup must be run in administrator mode message. Setup will now abort." It does this with even the setup disc that came with the card. MY OS is xp/mce2005. Anyone experience this issue yet?