I've seen people playing it on Windows 7 64-bit. Trust me, my spec is more than the listed recommended spec. Still, I couldn't even install it. The running the setup.exe, error message pops up "The version of this file is not compatible with the version of Windows you're running. Check... bla bla bla... nned an x86 or x64 version bla bla bla..
Help... How do I get past this?
This game ain't cheap
Make sure the UAC is not preventing the installer from running a process that it needs to run. It may be a spurious error message that is popping up in response to a situation the installer does not understand.