Originally Posted By: ToyotaNSaturn
sprintman, simple_gifts makes a good point, XP is a has-been.
I'm running W7 on multiple systems, from high end i7s down to old Pentium Ms. But XP is not a has-been just yet. It's going to be around for a while, at least until 2014. It is still faster than W7 and mature in a good way. It's stable with a lot of programs.
On an older system, there can be nearly insurmountable hardware hurdles getting W7x64 to run with 4gb. For those systems, the question is W7x64 or x86, or XP . . . with 3.25GB. I suspect that is the case here.
The OP can certainly run W7, but under 4GB it won't better XP. Without enough GPU, it could be a bit worse. In my experience, the video is the weak leg on older systems with W7. Unless it's an old gamer's rig, a 5 yo graphics system is going to have problems. The practical absolute minimum seems to be a nV6200/R9550. I'm not sure I'd burn $100 for W7 and barely/no aero on a box this old. For $30 or $50 . . . maybe.
If he can get SP3 aboard, he likely will see a slight improvement, and it will be supported for the remaining useful life of that hardware. Forget about that last .75 GB, though.