Sharing music w/ iTunes

Hey, I recently installed the Win XP, SP2, and iTunes 4.6. I really need to
be able to share music over the network with iTunes feature to do this, but
for some reason it doesn't work. When other people try to look at my music
it tells them they don't have permission or access is denied or something
like that, and I can't even see any other users. I'm guessing this has
something to do with the firewall, so I turned off the firewall in the
Security Center and I have tried it with iTunes checked and unchecked in the
exceptions box. Nothing works. Can someone please help?

Thanks,
Jared