[Rev Aristotle Jones]

Depending on what firewall you've got you may not need to do anything.

If you've got that bitch XP, go into network connections, find your connection and turn off XP's crappy firewall.

I use ZoneAlarm and I used to be able to host but then suddenly no-one could connect. I twiddled with ZA's settings, uninstalled it, reinstalled it everything and still nothing.

Then I checked the XP firewall - for some reason my computer had gotten all SkyNet on me and decided to turn itself on - P.O.S.