NANO Security's NANO AntiVirus is a relatively new entry into the huge market for free antivirus programs. Like the competition, it offers comprehensive, up-to-date protection from computer viruses, Trojans, malware, and suspicious programs. It monitors Web traffic, checks your e-mail, and keeps a tab on system activity in real time. It also scans RAM for infections and can even detect viruses in encrypted and compressed files such as archives and backups. Unlike many other free antivirus packages, it doesn't limit the features available in the freeware to get you to buy a premium version: All of its functionality is free. Many other antivirus tools, free or not, also use the same engines and definitions, but NANO Security has its own antivirus lab, and NANO AntiVirus has its own engine. NANO AntiVirus requires newer hardware, too: A 2GHz CPU, at least 2GB of RAM, and Windows 7 are recommended.
NANO AntiVirus sets up much like the other free AV tools we've tried, and its user interface bears the family resemblance in layout, controls, and access points, including a System Tray icon. But unlike some AV tools, NANO AntiVirus doesn't play well with others of its kind, including Avast! and Microsoft Security Essentials. NANO's Compatibility mode lets it run alongside other programs, but with compromised functionality (for example, we lost Internet connectivity when running multiple antivirus programs). NANO's full scan is thorough and can take more than an hour. It's actually several scans, including an initial RAM scan and fix that required a reboot to remove a pair of minor infections that our regular antivirus program missed because it doesn't look for them. You may need to run NANO as an Administrator or enter your Admin password to scan some programs, though we could check Skip or Allow All.
We should note that NANO AntiVirus has no relation to the similarly named rogue program from several years back. In fact, it's a fairly new project, so it still has some touches of the beta here and there. But NANO AntiVirus is also something else, a genuine alternative to the dominant players in a competitive field.