I buy 'built' computers. No 'brand loyalty', but I *am* familiar with HP's recovery DVD system, etc, so I just bought a new HP. All their upper level, *real* systems are 64 bit. I haven't had a single irregularity that I could pin on '64 bit'. I have had a couple times my Logitech mouse messed up, but that is IT. I am 'currently' running W7, as I am wringing it out, to know what I can of it before somebody I know buys a new computer and asks me questions. There are 'little' things about W7 that are awkward for me, and I expect in a while to go back to VISTA-64...which I both like, and never had problems with, except the mouse thing. I *suspect* I can cure that by using the HP corded optical mouse, but IT doesn't 'wheel' something I ALWAYS 'wheel'. Point of fact the best computer in the house is VISTA-32; runs PERFECTLY, all the time! ....But I can't buy a new, upper level, 32 bitter, etc...etc...etc.
Lots of blarney here, maybe some part of it will help you... I tried.