The publisher Avira calls it Antivir. Who knows how it's supposed to be pronounced? What it's called doesn't matter as much as what it does, though, and Antivir is another in a growing list of free antimalware and antivirus programs that does its job well.

Antivir runs a real-time guard permanently in the background; although you can shut it off, there doesn't seem to be a way to remove the icon from the system tray. Having encountered applications like this in the past, that's a huge red flag flailing in the wake of your PC's cooling fan. So, after testing Antivir on two Windows XP boxes and a Vista Enterprise machine, I was quite surprised to find that there was no noticeable depreciation in clock speed among any of them. Of course, that doesn't mean it can't or won't happen, but it still was a pleasantly surprising turn of events.

Another pleasant surprise was that Antivir gives the user full control over nearly every aspect of malware scans--again, keep in mind that this is the free edition. The heuristic scan can be turned on or off completely or partially, and you can also set it to three different intensity levels.

Antivir\'s main panel uses tabs and drop-downs to make navigation uncluttered. (Credit: CNET Networks)

The scans were just as thorough, allowing the user to fully scan all hard drives, or limit the scan to just the Windows system folder, active processes, rootkits, or any combination of those, or to the half-dozen other pre-loaded scans. Combining the antimalware with antivirus protection is a smart move, and that usually is only available in editions. No viruses were found on my machines, although several hidden files that weren't tracking cookies did rear their heads.

The only problem with a complete scan is that Avira isn't joking when it calls the scan "complete"--it took more than three hours to scan one of the Windows XP machines, and that was the fast scan. The application will stop mid-scan, as I found out the hard way, and let you know when it's found a threat or maliciously hidden file. This is good for killing nasties as soon as they're found, but it means that you have to babysit the program.

The quarantine was thorough, too. The spreadsheet-style screen displays all relevant information about a quarantined file, and gives you options to scan it again, restore it, delete it, and send it to someone--presumably your IT department or the Avira folks, not distribute it around the Internet. The scheduler lets you set your own update schedule, as well as schedule scan jobs of varying intensities and focuses.

The updater worked slowly, which would be a fairly big gripe except that Avira makes it easy to go to their Web site and manually download a new definitions file. The help features in Antivir were quite thorough, with an easy-to-find description box giving easy-to-understand mouse-over information on each feature. If you're unfamiliar with heuristics, for example, this could go a long way to helping you build your knowledge base.

Overall, Antivir will take a while to get used to with its interface and wealth of available features. But as long as the definitions file updates keep coming, this application's a keeper.

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