"Free antivirus programs vary just as much as paid security programs do in the quality of their protection. And frugal computer users on the hunt for no-cost antivirus software — already faced with tons of options — will have even more to choose from when new free offerings from Microsoft and Panda join the programs currently available from Alwil (Avast), AVG, Avira, Comodo and PC Tools.
To help you figure out which free antivirus app is right for you, we put packages from all of those companies through their paces. Our testing partner, AV-Test.org of Germany, employed its vast "zoo" of collected malware to test detection rates and scan speed. We then poked and prodded the apps to see which ones made stopping malware an effortless task, and which ones made it feel more like drudgery. " – Content courtesy of Can you trust free antivirus software? – PC World- msnbc.com