Re: Mass Effect to x64

ME3 (and the vast majority of commercial applications these days) are still 32-bit.  Windows has had a 64-bit version since XP, all of which will run 32-bit programs just fine. 

You'll notice that most of your programs, including ME3, get installed into "C:\Program Files [x86]".  That's the folder for 32-bit programs. 

"C:\Program Files" is where Windows will put a native 64-bit application (if you ever find one!)