Wait, what? Hang up as in...slow down? You probably need more RAM, which is Random Access Memory. Do you know how much RAM you have? In WinXP, click Start, then Right Click My Computer. It will be listed under Computer, at the bottom.
In simple terms, how much RAM you have is, essentially, how quick your software will run. Think of it like a comb. The longer ["more"] comb you have, the easier it is to comb your hair [i.e, get the job done]. If you have a little amount of comb, it'll be hard to get the job done. (That explanation isn't great, sorry. But, just remember that more RAM = faster program execution.)
Edit: Also, try a disk cleanup/defragmenter. Reinstalling XP won't do you any good, unless you have an enormous amount of stuff saved on your hard drive, and are willing to erase it all to make your computer more efficient.
More RAM will always help; upto a max of 4GB if you are running a 32-bit OS.
Aside from that, some general 'cleanup' of Windows might help to restore performance. This is assuming your hardware has no problems:
+Anti-virus scan with a good virus scanner- AVG/Avast/kaspersky.
+Anti-spyware scans with Spybot S&D and malwarebytes.
+Disk cleanup to delete old temp files and other junk.
+ Full disk defrag including defrag of system files like the MFT, if required. Diskeeper 2009 is an excellent utility for this since it's fast and thorough.
+Disable unnecessary background processes and services that take up memory.
+Upto date drivers and Microsoft critical updates.