Roger on MikeC's advice.. I used to run SW Firewalls until I started networking. Just bought myself a refurb Cisco Hub/Firewall and let that handle everything.
Additionally, XP Home doesn't load printer and file sharing in the default load. You have to manually make Windoze load it.
Go to view network connections, right click on the card you are using to network. I can't remember what option you have to click install on, but it brings up the File and Network sharing module to install. I have home on all 3 of my networked computers and share files just fine.
Pro installs all of this automatically, that is why you find lot's of Pro Fanboys.
(No insult intended to the above Pro Fans)