While AVG, Microsoft, Comodo and avast aren't the only providers of free anti-virus software they are some of the most popular so if you are sick of paying every year for antivirus protection, we'll help you decide which free program works for you. Let’s check them out:

avast Antivirus 6

First, let’s take a look at the free offering from AVAST Software for home users: avast Antivirus 6. It includes virus, spyware, and rootkit protection. In addition to the basic functionality, here are some of the advanced features you’ll find:

Real-time shields: The file system shield monitors and scans files you open, save, and store on the computer. It serves as the main component of protection and is similar to other real-time scanners. However, avast also provides additional shields that monitor specific connections to potentially detect infections before they actually get to the file system. These shields monitor mail, Web, P2P, IM, and network traffic. The script and behavior shields also provide detection of scripts and suspicious behavior.

Auto sandboxing: Automatically runs suspicious files in a virtual isolated environment so no damage can be made to the actual system. Manually running files in the sandbox is only provided in the premium editions. However, when avast detects a suspicious file the user is prompted with info about it and asked whether to run it in the sandbox, normally, or not at all. If ran in the sandbox, the program will have a red border. You can play in the sandbox with a test program.

Boot-time scanner: Can be enabled to run a scan before Windows loads the next time you reboot. Since it has direct drive access, it may be able to better remove rootkits and other stubborn infections. Site blocking: Optionally list URLs to block users from visiting. Though only a basic filter, it’s a great bonus feature.

Virus alerts: Can notify others of any viruses that are detected, sent via email, printer, or network message.

Password protection: Protect the avast components and settings with a password, so your children and others can’t play with or disable it.

No matter which antivirus solution you use, it’s best to run weekly full scans to make sure no infections have made it through. Some antivirus programs auto schedule this for you, but avast doesn’t. But don’t fret, simply click Scan Computer, click More Details for Full System Scan, click Settings, and select the Scheduling tab.

To answer any questions you may have about the terms in this article please visit Webopedia, our free online dictionary of tech terms.

Comodo Internet Security 5.3

The Comodo Internet Security suite offers free protection for both homes and businesses. In addition to virus, spyware, rootkit, and bot protection, it comes with a firewall. It also has even more advanced features, including:

Auto and manual sandboxing: Untrusted executable files and programs are automatically ran in the virtual environment so modifications can’t be made to the real system. This is similar to avast, but Comodo lets you manually run programs in the sandbox at your choosing. You can also view and manage the trusted and unrecognized files.

Web filtering: This DNS-based service helps to block known dangerous websites at the browser before you have any chance of becoming infected. But if you want to block specific sites or categories, you’ll have to use a different solution such as OpenDNS.

Advanced customizable polices: Comodo is highly customizable with advanced settings. You can create a computer security policy as a part of the Defense+ component and a network security policy for the firewall.

Configuration management: Maintain, save and export multiple configurations of your settings. Great for backup purposes or for deploying multiple computers.

Password protection: Protect components and settings with a password to prevent children, employees, or others from changing settings or disabling protection. Optionally suppress alerts to prevent users from doing damage, such as ignoring a virus.

Currently, Comodo is offering a 60-day free trial of GeekBuddy, a live remote PC support service. When you install Comodo Internet Security you can choose to also install their remote software that you can use to request assistance.

I should point out that rootkit scanning isn’t enabled by default in Comodo Internet Security. The vendor said this is because it may create false positives that can’t be distinguished by average users. However, if you think you’re able to, you should enable it.