Software firewalls that are payware are a hard sell because a basic two-way firewall that watches inbound and outbound traffic on a computer is all you need. So the freebies cover this category quite nicely .
The free edition of Zone Alarm firewall is a great choice for home computer users with some Internet experience. Although it's not as streamlined as some other firewall applications, it keeps things basic and easy to use. The paid version of ZoneAlarm automatically decides which programs can access the network. With the free version, users must permit or deny a program's access to the Internet. This might be tedious if you're unfamiliar with which programs access the Internet on a regular basis. It can also be dangerous if you unknowingly permit access to an untrustworthy program. Free is good; the Pro version, as you would expect, is better, especially since it also offers virus and spyware protection. Highly recommended!
Sygate Personal Firewall Standard
This free firewall is geared more towards experienced users. So steer clear if you're new to computers. If you're familiar with home networking, this application might be for you. The program interface is very technical. A graph shows you how many attacks your computer has received and the level of network traffic. It does not configure itself automatically, so you'll often be prompted to permit or deny network access.
McAfee Personal Firewall Plus
Yet another component of McAfee's many security applications, Personal Firewall Plus is a software firewall aimed to keep intruders out. The application, which is available as a standalone product, automatically determines which programs are allowed to access the Internet. At the same time, network ports are closed so intruders can't gain access to your files. You're rarely prompted to deny or permit Internet access to an application because the software configures itself quite well. You also manually open ports using the System Services utility, which is a helpful tool for advanced users.
Norton Personal Firewall
This product, sold alone or as part of Norton Internet Security, is a competent firewall that bugs you a lot about outbound traffic, though perhaps just as much as Zone Alarm and McAfee Personal Firewall. But it's not so smart. For example, it detected F-Secure Anti-Virus trying to communicate with the outside world and recommended that it always be blocked. If I pay for a firewall, I want decent accuracy on recommended actions by the software. F-Secure is a Symantec competitor so I have to wonder about Symantec's motives on this. I am not a fan of Symantec 's security products in general, and while Norton Personal Firewall isn't completely offensive, it rubs me the wrong way.