Important note: Only install one antivirus on a computer at any one time, installing two or more can cause your computer to become unstable and crash!
1. Avira AntiVir Personal
A top scorer in antivirus testing done by
www.av-comparatives.org, the free version of this paid-for software offers protection against viruses, worms, trojans, dialers and phishing, but NOT against spyware and adware (only available in the paid for version).
http://www.free-av.com/2. avast! Home Edition
Another high scoring free antivirus including the famous GMER anti-rootkit technology. Requires registration to obtain a "free" license key.
http://www.avast.com/eng/free_virus_protectio.html3. AVG free edition
Probably the most well known of the free antivirus programs, AVG offers protection against viruses, and a safe search feature which will scan search results and give them a green/yellow/red rating and advise you of any possible security risks they found on that site. Does not have anti rootkit in the free version.
http://free.grisoft.com/ww.download-...s-free-edition4. BitDefender 10 Free edition
Created by a well known Romanian antivirus company, BitDefender also forms the basis for a number of well known anti virus products including GData Antivirus.
http://www.bitdefender.com/PRODUCT-1...e-Edition.html5. ClamWin
ClamWin is a free, open source antivirus initiative.
http://www.clamwin.com/6. PcTools Antivirus Free edition
PcTools, creators of "Spyware Doctor" and now owned by Symantec Corporation, have created a free version of their "PcTools antivirus"
http://www.pctools.com/free-antivirus/7. Comodo Internet Security
Complete protection including antivirus and firewall from creators of the Comodo Firewall Pro.
http://antivirus.comodo.com/8. Dr. Web CureIT (Standalone utility)
Dr. Web CureIT is a standalone scanner created by the russian antivirus company Doctor Web. It is not a replacement for a resident antivirus, but can be used alongside your current antivirus for periodic scans. Has full cleaning abilities, but no built-in updater, so a new copy must be downloaded each time to have the latest virus signatures. Handy for cleaning out badly infected machines as it requires no install, and can be run from a flash drive.
http://www.freedrweb.com/cureit/9. Kaspersky AVPTool
Well know Antivirus company "Kaspersky Lab" has developed a free utility, called AVPTool which can scan and clean machines using the same signature database as the paid for Kaspersky Anti Virus. The utility does not have a built in updater, so a new one must be downloaded each time to have the latest virus signatures.
ftp://ftp.kaspersky.com/devbuilds/AVPTool/index.html10. SUPERAntiSpyware Free edition
A free, easy to use spyware scanner. Comes with regular updates and removes most types of spyware including antivirus 2009 and zlob.
http://superantispyware.com/download...NTISPYWAREFREE11. MalwareBytes Anti-Malware free edition (Anti spyware)
A program created by some of the web's leading security community members. MalwareBytes Anti Malware is a relatively new program, but is already making a serious reputation for itself, keeping up to date with most recent spyware threats and cleaning them with ease.
http://www.malwarebytes.org/mbam.php12. Rising Anti Virus Free Edition
Brought to you by a Chinese security company, a popular Asian antivirus- Rising AV.
http://freerav.com/