UAC . . . . . turn it off and you can run anything on Vista 64. When you turn off UAC Vista 64 (and Vista 32 for that matter) turn into baically XP with a kick ass UI. My computer does kick ass with games in Vista 64. The ONLY drawback to 64 is here at cheathappens, most of the trainers do not work on 64 bit architecture due to 64's security architecture. **shrug** That's what dual-booting is for :-)