Look at it this way if you go with XP64 there is a chance that you'll encounter some issue running SOME applications and obtaining SOME drivers. I would go to the manufactures website and get the 64 bit drivers directly from them rather then trust a third party on this. You lose nothing by going with XP 32 bit. Unless your looking to use 64 bit enabled software I would stick to the 32 bit version of windows XP until Vista comes out. Vista is supposed to come out at about this time next year.