I'm confused!! I got a new mb (AMD Phenom II X2 550 3.10 ghz, 2.00gb ram)- my son tried to install our win xp 32 disc on it. It installed, then crashed on windows update and wouldn't boot. total shut down So - he got win xp64 and installed that - it's a total pain in the rear. Will only download some windows updates, some download after multiple attempts, some won't download at all. So, my other son offered me win 7 - only the disc he's given me is 32 bit! Is there any point in asking my younger son to try to install this? or will it not work with athlon dual core? I'm guessing we're not likely to find both versions are on the disc when we try to use it.