Correction, you need a 64 bit operating system, not windows specifically =P
32 bit code could access > 4 GB of RAM. 32 bit OSs access 1+ TB hard drives no problem. Only thing is that you can't fit all that in a single CPU register. Old old 8 and 16 bit CPUs used to use a convoluted scheme to access more memory than could fit in a register. It was just dog-ass slow. So there's nothing carved in stone that other OSs have to have that same limitation
XP pre-sp2 and all 32 bit Windows Server systems can access more than 4G of RAM. The only reason the limitation got put in at XPsp2 is because the driver writers kept screwing up the hoops you have to jump through to deal with it.
32 bit Linux can also access more than 4G, just most don't have that flag turned on by default in the kernel build.
I could probably build you a quad-core system with $300. You just need to know which parts to skimp on and which parts not to, as well as which parts to salvage from your old system and which parts not to. Hell, if you want to drive up to Salem I'd probably build it for you, too, I don't do much else on weekends except sleep off hangovers.
