Note: This review addresses version 3.13.121240.574.

Willing to put up with some annoyances to get great free firewall protection? Check out Comodo Firewall, an extremely effective protection tool for keeping yourself safe from Internet dangers. It blocks Trojans, hackers, and other threats--without charging you a penny.

When you install Comodo Firewall, you have a choice to install only the basic firewall, the "Firewall with Optimum Proactive Defense" (which also protects against malware which can bypass firewalls), or the Firewall with Maximum Proactive Defense+ (which does what the former does, plus protecting against "leaks"--information about things such as open ports being sent out over the Internet). The higher the level of protection, the greater the firewall's intrusiveness. You can change the level of protection later, when you're running the program.

Installing the program requires close attention. At defaults, you could end up with bundled products and unwelcome surprises. After downloading the entire Comodo Internet Security package, you can choose to install an antivirus application, the firewall, a 30-day trial of Comodo's LivePCSupport, or any combination of the three. For this review, we installed only "Firewall with Optimum Proactive Defense."

During installation the Comodo Firewall will change your default search engine to Ask.com, make Hopsurf.com your home page, and install the Hopsurf.com toolbar--unless you uncheck those options. And you can also opt to use Comodo's DNS servers instead of your default DNS servers, although the default is to use your own.

Once you're in the program, though, things get more straightforward. After you install Comodo Firewall , when an application needs to make an Internet connection, the firewall will ask whether you want to allow that connection. If you know the app, allow it to make the connection; if you don't, tell the firewall to block it. Comodo cuts down on the number of these annoying pop-ups, because it knows about a number of applications that are safe--such as browsers and e-mail clients--and lets those through without question.

For basic operation, that's all that you need to know, but if you want to customize Comodo's functioning, you can do that as well. There's a wealth of techie information available. Most people won't need it, and will be satisfied to let the firewall work on its own.

If you use Maximum Proactive Defense+, you'll be asked when programs try to make certain system changes, such as altering portions of the Registry. You'll have to balance safety with being annoyed. You can also turn that part of the program on and off.

More important than interface of a firewall is effectiveness, and here Comodo Firewall Pro shines, according to the Matousec.com set of firewall tests. It rates Comodo Firewall Pro well ahead of other firewalls--over the last year, the firewall rated 95% every time it was tested. By way of contrast, Norton Internet Security's firewall ratings range between 66% and 71%, McAfee's were at 12%, Panda Internet Security between 4% and 12%, ZoneAlarm Free at 11%, and ZoneAlarm Pro at 72%.

If you're willing to put up with a very annoying installation procedure, and you don't mind occasional interruptions, Comodo Firewall is a keeper. It's strong, and you certainly can't beat the price. If the installation issues turn you off, you might want to try a less intrusive firewall, or just use what's built into Windows.

Note: This software comes in 32-bit and 64-bit versions. This is the 64-bit version, which is for 64-bit PCs running a 64-bit OS. If your PC is running a different supported OS, please download the 32-bit version instead.

--Preston Gralla