Black Ice is a brilliant Firewall/Security program for Windows. It is by far the best non-professional firewall I have ever seen. Since you can purchase it for around US$40, as opposed to US$200 + for a professional firewall, Black Ice becomes both economic and effective. This program does have shortfalls, a dedicated hacker could bypass it, but such hackers would not be attacking random home users. Businesses may find a professional firewall a must, however the average home user need look no further than Black Ice. It blocks all suspicious activities, whether they be incoming or internally executed. It will popup with a box warning you of a potentially dangerous action, and give you the choice of terminating the action or continuing with it. It also traces IP Adresseses and will auto-block them when they attack. It also has varying degrees of protection: Trusting, Cautious, Nervous and Paranoid. All in all, a great program for a great price. Need a firewall, this is the program for you.

Note: This program is compatible with Windows XP (after an upgrade to version 3.5), even though it warns you of incompatability.