There are many free, excellent firewalls available. Two that I have used and can recommend are Comodo and Sygate. While both are simple to install, no firewall is completely simple to use---you must "train" it so that it knows what applications are permitted (by you) to have internet access.
Since these firewalls are free, you can certainly download one and give it a "test drive" and "kick the tyres" for two weeks. Just an important reminder: do not have more than one firewall running on your computer, since having several can cause not only performance slowdowns but serious conflicts.
See the list below for the links to these two firewalls (as well as others used by BC members):http://www.bleepingcomputer.com/forums/topic3616.html
If you have never used a firewall, there is a good BC Tutorial
that will help you understand how one works:http://www.bleepingcomputer.com/tutorials/understanding-and-using-firewalls/
Edited by jgweed, 20 June 2007 - 11:10 AM.