I have Vista Home Premium 64 bit... couldn't be happier! This has been the most painless build I've ever done. Have 4gigs memory right now... which 64bit recognizes, but will probably have 6 or 8 gigs within a couple of years. 32bit no matter what version u get.. will only recognize a little over 3 gigs. Just be careful and get the drivers that are 64bit compatible.