I am finding stuff that doesn't play in Vista 64 bit WILL play in Windows 7 64 bit. I don't know about that one though ( I played it on the PS3 ), but if the box says it will run in Vista 64 Bit, than in all likelyhood it will run in Windows 7. In both Vista 64 Bit and Windows 7 64 Bit, you actually have two set of files, x86 ( 32 bit ) and x64 ( 64 bit ). If the game is written to x86 ( and it is ), it be installed in the x86 folder and run from there. I just got Mass Effect and Mass Effect 2 yesterday. Mass Effect didn't run in Windows 7 but ME2 did. I will try Mass Effect in Vista later ( I also have an XP machine that I know it will run in ).