The paid-for version of Alwil's latest antivirus software, Avast 4 Professional Edition, disappointed us, despite a decent, 92 percent success rate at detecting malware. It caught only 37 percent of the malware in our proactive tests, the second-worst showing of any of this year's big antivirus programs. And it lacks phone support.

Avast's performance was about average in our disinfection tests. It cleaned all infected files, but missed changes to the Hosts network settings file and some Registry entries, catching 78 percent of all possible items.

The program installed smoothly, with appropriate default settings for the average person. It offers two interface options. One is a distinct, media player-type control panel that makes it easy to figure out how to launch a scan or set a manual boot-time scan; a second 'enhanced interface' lets you access and fine-tune more settings, but it's not nearly as user-friendly as the other option.

After installation, Avast runs one full-system startup scan. But in the awkward advanced interface, we could not find a place to set up a regularly scheduled scan. One option enables scans whenever the screen saver is running, but again, this program setting was difficult to locate.

The program scans a good range of email and news protocols, including POP3, SMTP, IMAP and NNTP. It also scans all web traffic. And Avast's comprehensive instant-messaging protection fully supports AIM, ICQ, MSN, Skype, Trillian and Yahoo Messenger instant-messaging programs as well as lesser-known chat tools such as Gaim, Miranda and Pal Talk Messenger.

Upon installing, Avast places on your PC a useful, built-in Virus Recovery Database, which you can theoretically use to repair infected program (.exe) files (we didn't test this functionality).

Test results and verdict on the next page >

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