Yes. The 4 gig patch flips some bits in the executable file's header, and lets Windows know that the game can address more than 2 gig of RAM. You do need a 64-bit OS and more than 4 gig of RAM for them to function correctly. Older versions of Windows (XP), you could use the Boot.ini to tell Windows to allow an enabled app to do that. The newer 64-bit OSes do it automatically, while a 'modern' 32-bit OS with 4 gig or more of RAM has to be "told" a different way to do it, which can get rather involved.
