Avast Free 5, an A-list freeware antivirus app, provides the same steadfast protection of well-known, pricier antivirus programs. Avast is remarkable for both its effectiveness and arguably providing the most complete free antivirus on the market.

Avast Free 5, formerly known as the Home Edition, protects you with multiple guards. The antivirus, antispyware, and heuristics engines form a security core that also includes multiple real-time shields. The adjustable mail and file system shields join the pre-existing behavior, network, instant messaging, peer-to-peer, and Web shields. The behavioral shield is a common-sense feature, as security software publishers leverage their large user bases to detect threats early and warn others. Other new features include a silent-gaming mode and an "intelligent scanner" that only looks at changed files after establishing a baseline. The biggest change in Avast 5, though, is the interface. Gone is the music player default look, which was skinnable but confusing. In its place is a sleek UI that new users should find far more manageable. It's also Aero-friendly, with Explorer-style navigation buttons in case you can't remember where you tweaked a particular setting.

Avast's recent independent third-party testing has been notably solid, able to hold its own against better-known programs from Symantec and Microsoft. Avast 5 Free lacks features in the paid upgrade including antispam measures, a testing sandbox, a Script shield, and a firewall. Even without those, Avast Free 5 is probably the strongest, free antivirus currently available.

Avast Free Antivirus is based on multiple protective layers that work together to provide security. The product is designed for the average consumer who wants easy-to-use protection for basic email and web surfing. It is limited to home and non-commercial users.

New features match top detection with increased efficiency. Computer memory requirements for the new antivirus and antispyware engine have been cut in half. Scanning is 40 percent faster, saving both time and computer resources. Complete rootkit protection includes real-time detection to ward off initial installation, on-demand scanning and boot-time scans. The user friendly 5.0 has a new interface with easy-to-adjust settings, a context-sensitive help menu and graphs showing ongoing protection activities. Users can set the time and conditions for complete scans, with avast even waking up their computer from hibernation for midnight scans before putting it back to bed. Multiple shields prevent the spread of malware via email by checking incoming and outgoing emails for suspect content, identify malware by its anticipated behavior or by looking out for unusual activity and attempts at system modifications.