"If" I were going to all that work, I think I'd dig up four more gigs of memory and go 64 bit. Otherwise I'd be inclined to just let it go as is. I'm betting MAME will be running on XP for a good while, regardless of Microsoft support. There is just too much of the community that has such deep roots with XP for it to just suddenly be abandoned! Some potential roadblocks I could see upgrading would be: If it's high performance DDR2, like 8500 stuff, this could be to expensive to be worth it. I haven't checked the used market for this lately, but it was still bringing in pretty decent money not long ago. If not, and assuming you've got a 775 board, you could always stick a q9550 or 9560 in there at some point down the road for a little more oomph, without a major hardware upgrade. My logic on this has always been, that I'm not expecting many of the CHD's to run, much less run perfectly, so as long as the classics are hanging in there, why not make the most of the hardware you already got. It's a hellava lot cheaper this way! My understanding is the higher performing dual cores still hold their own, since MAME doesn't use more than two cores anyway. To me, that means in the older procs, i.e. a E8500 or 8600, would still fair well, and they run 64 bit windows good too. I've got a 8500 running 8.1 in my HTPC, and it still holds it's own.