Just because threats to your PC continue to mutate doesn't mean that you need to pay for peace of mind. CNET editor Rafe Needleman explains his reasoning for why you should go free when it comes to security programs, and in that spirit we've collected some of the top free antivirus programs around.

There are currently six excellent free security programs on CNET Download.com that are rated four stars or higher. These include the three most popular programs on the site: AVG, Avira AntiVir, and Avast, as well as ThreatFire from PC Tools. There are also two cloud-based security solutions in the group, Microsoft Security Essentials, which replaced the company's OneCare paid suite, and Panda Cloud AntiVirus.

This can't be stressed enough, but none of them will replace smart browsing habits. For example, Google announced earlier this week that fake antivirus scams account for 15 percent of all malware. Check out our Security Starter Kit for a collection of additional free security tools, including spyware removers and in-browser security.