Yes, the game will work on Windows 7 64bit, but since it's the multiplayer part of Wolfenstein, I can say that you will not have the possibility to play only with other people because it requires Punkbuster. The problem with Punkbuster is related to compatibility. There is no version of this anti-cheat module available for Enemy Territory on Windows 7 64bit. If you attempt to play on a multiplayer server, the system will kick you out in a few seconds.