Hi, I have a 32-bit operating system of Vista Home Premium, with 3 GB of RAM, and a processor running at 2 GHz. I have passed the system requirements from Windows Upgrade Advisor. I want to upgrade to Windows 7 Professional, but I'm having a difficult time deciding which OS to choose from in Windows 7 Professional. Windows 7 Professional (x86) or Windows 7 Professional (x64)? It's a bit embarrassing, but I'm afraid I don't know the difference between the two. I would be grateful if someone could explain it to me. Thank you.