Illustrations by Andrew BanneckerFree 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. For a summary of our findings, see our free antivirus software ranked chart. For our in-depth evaluations, see the individual reviews, linked in this story and in the chart.

Something-But Not Everything-For Nothing

While free antivirus programs give you some value, they don't have everything that a paid security application can offer.

For one thing, you won't have anyone to call if things go haywire, or if you need disinfection help in the event something does sneak past your PC's defenses. Most free apps give support only on online forums, though Avast offers e-mail support (and Microsoft plans to when Security Essentials launches); Avast users can submit online support tickets, too. AVG gives paid phone support, but the -per-call fee costs more than most paid antivirus apps.

Generally, free apps have less-frequent malware-signature updates than paid products do, which can leave a window of opportunity for brand-new baddies to evade detection. Most of the free apps we tried update their signature databases only once daily. Microsoft Security Essentials, however, will also check suspicious samples that don't match a particular installed signature, by running the sample against Microsoft's latest online signatures. And as long as you have an Internet connection, Panda Cloud Antivirus checks everything against Panda's servers, so it will always use the newest signatures. (If you don't have an Internet connection, the Panda program falls back on local caches.)

Source: www.pcworld.com