The only way to know is by installing and running it there. Some 2005 games won't even install on Vista. One good example is Metal of Honor: Allied Assault. That simply refused to install when tried. Surprisingly much older games like Return to CastleWolfenstein and Soldier of Fortune I+II seem to run better there then seen on XP. Those were far less dependent on having the latest video and sound drivers installed. Having a good 2gb of memory usually helps as well as exiting any antivirus programs when for gaming sessions.
