Avast Free Antivirus

Avast made great strides in its previous update. Version 5 set the stage for the modern, massively popular, and free security suite with a new interface that ditched a quirky, late-'90s jukebox style for a more polished look. Easier to navigate, it also became easier to add new features.
Make no mistake; Avast 6 adds features both big and small. Some that had previously only been available to paid upgrade users are now free for all versions, and newer features have been seamlessly added to the interface experience. If you're familiar with Avast 5, upgrading to Avast 6 won't be that big of a leap.
Features and support
As mentioned, the two big new features in the free version of Avast 6 are the AutoSandbox and the WebRep add-on. The debut of the AutoSandbox makes Avast the second antivirus option to offer a sandboxing tool for free. Competitor Comodo introduced a sandboxing tool in January 2010. Avast's sandbox probably works differently, as Comodo has a pending patent on its version. And certainly, one of the most frustrating things about sandboxing technology is that there are some indications that it doesn't work perfectly.
The AutoSandbox, new in both free and paid Avast versions, automatically places suspicious programs in a virtualized state when it suspects them of being threats. As the program runs, the sandbox keeps track of file behaviors and what it reads and writes from the Registry. Permanent changes are virtualized, so when the process terminates itself, the system changes it made will evaporate.
Performance : As far as Avast's impact on system performance goes, in a real-world test Avast completed its scans in a timely yet not blazingly fast manner. A Quick Scan took about 20 minutes, and the Full Scan took 59 minutes. RAM usage was surprisingly light, with Avast 6 only eating up about 16MB when running a scan.
There were some notable areas where Avast did well. Avast had a minimal impact on startup time, with Avast Internet Security 6 adding 6.25 seconds, Avast Pro Antivirus 6 adding 5.76 seconds, and Avast Free Antivirus 6 slowing down the boot cycle by around five and a half seconds. All three posted a tiny impact on system shutdown, around 1.3 seconds slower than an unprotected computer. Scan times as well were competitive, slower than AVG, Trend Micro, and Panda, but faster than most competitors including Microsoft Security Essentials, Norton, and Ad-Aware. Also, Avast Pro Antivirus posted the best Cinebench score we recorded. Avast's one point of weakness in the lab was its MS Office decoding test performance, where it was slightly slower than average but by no means the slowest suite tested.

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