It's capability determines whether the processor is compatible or not. If it's of the same socket type, there's a good chance it will work. I can't tell you if the board will auto-configure the processor. As well, XP is going to see the change and you might have to reactivate. If the processor works, you will probably see a small performance gain but it looks as if your RAM is still going to be a bottleneck. You should be at 1/2 gig or more.
My computer currently has a 1.80 Ghz pentium 4 processor. I am running 128 megs of ram on windows xp. I have an extra pentium 4 processor with 2.80 Ghz. Can i swap out this processor with hurting my computer and if it will make it faster?