If You haven't re-installed Winxp since the problem started, I 99% guarantee that a re-install will solve your usb problems.
The USB on my computer is totally F***ed! Maybe I can get it working soon...
Has your USB always been broken? You may want to check to make sure it's properly enabled in your BIOS.
Nope, when I first got my Micro-Crap Internation (MSI) mobo, it worked... now... it doesn't

I don't even remember exactly when it broke... the wierness started with my MP3 Player though...