First, I'm sorry if this is in the wrong place, but I couldn't see a forum section related to PC's and software. I have a AMD Athalon 64 FX-57 processor, 2 GIG of Ram and a Win XP pro 32 bit Operating system. If I upgrade to the 64 bit version, will I notice a big difference when using and playing games on my PC? Would it be worth spending the money for the difference it would make? Also, what is the difference between OEM and retail versions, apart from the price. Would I be ok going with the cheaper OEM version? Thanks in advance.