As I can see from your specs, you have a 13gb hd...so most likely, you dont have except that 2 gigs of free space...As Makaveli213 said, it all depends on what you are going to install on it (other than the os)
Also, if you are planning on installing XP Pro as a second OS, then I think itll be a little annoying...given your pc specs (p3, 256mb ram...)
If you really want XP, then I would sugest having it as the only OS on your pc...then, youll have some more disk space available...Itll also be a little anoying but itll definetly be better than having it as a second OS and running on a 2gb partition...