Firewalls are often your first line of defense, but if you're using anything older than Windows 7, the default firewall just won't cut it. Even on Windows 7, the Microsoft firewall doesn't provide outbound protection. These tools will shore up your 'wall.
Comodo Internet Security merges Comodo's well-respected free firewall with its antivirus program. Though the AV is good, the firewall is better, and thankfully users can choose to install each component separately. It's eradicated most of its resource-hogging ways and gives users what they want: a flexible yet simple firewall that's great for beginners but also provides a smorgasbord of information and plenty of options for advanced users. Read full review
Online Armor has a professional feel that is typical of freeware versions of advanced security tools, pared down to its firewall options. The installation is blazingly fast, taking less than 30 seconds from double-clicking on the installer to running the firewall. Once installed, Online Armor defaults to running its installation wizard, which it calls a Safety Check.
In addition to the firewall, which configures as much as possible during the start-up wizard so you're not bothered later, Online Armor comes with a keylogger guard, tamper protection, malicious script and worm protection, and limited autostart protection. Online Armor defends you from a wide range of sophisticated attacks.Read full review