A Personal Firewall is typically software that is installed on one machine and is used to block or allow communications going to and from that computer using a security policy.

There are 2 major benefits for using a Personal Firewall.

1. Protect your computer from being broken into
   Computers from around the world get broken into and become “zombies”. They are controlled to search the Internet and try to take over more machines. A good Personal Firewall will block attempts coming from the Internet to break into your computer. An unprotected computer can be broken into in as little as 15 minutes from being hooked up to the Internet.
   
   Once your computer is broken into your personal information is at risk.

1. Block software on your machine from getting out
   When software on your computer sends information out on the Internet that you don’t know about or don’t want shared, that is called a “leak”. A good Personal Firewall includes “leak protection” which blocks software on your computer from communicating on the Internet if you don’t allow it.
   
   Malicious software called “spyware” is created to infect a computer and steal personal information. When Spyware tries to “phone home” leak protection can block the communication. Typically it will ask you if you want to allow the communication because it can’t always tell what is a program that you want and what is Spyware. This gives you a chance to tell the Personal Firewall if the program trying to communicate should be permitted to do so.

Please note that not all programs trying to access the Internet are bad. Some are valid programs checking for updates and more. I had a friend who blocked anything and everything that tried to communicate over the Internet and was left with a machine that couldn’t do very much at all. If you are unsure of something, Google it to find out what it is.

KDC Free Pick

Windows: Comodo.com – Free and commercial versions

Recommendations

We recommend you consider the following options. They are in no particular order.

• ZoneAlarm.com – Free and commercial versions.
• Comodo.com – Free and commercial versions.
• Online-Armor – Free and commercial versions.

Important Tips

• Do not install multiple firewall products at the same time.
• Microsoft XP Service Pack 2 and later includes a built-in firewall. This should be used as a minimum of protection. The downside with this solution is that it doesn’t notify you when something new and unknown on your computer is trying to access the Internet. It is silent in this regard and doesn’t offer the “leak” protection mentioned previously.

More Information

• FirewallGuide.com – Personal Firewall reviews and tips.
• WikiPedia.org – Personal Firewall article
• WikiPedia.org – Firewall Comparisons article (technical)