Easy-to-use firewall blocks hackers and other unknown threats.
Systematically identifies hackers and blocks access attempts
Automatically makes your computer invisible to anyone on the Internet
Information about Firewalls
Free Software Firewalls
Some Advice:
Try to use a router whenever possible for the added hardware layer. Windows XP SP2 has an adequate firewall, coupled with the router (check with your ISP for bundled deals that may be available!) is an excellent step in securing your online experience.
