Norton AntiVirus 2005 offers both antivirus protection and (new in this version) a simple firewall. A new Preinstall Scan works around infections that attempt to prevent NAV's installation. It automatically and silently downloads and installs virus signature updates and can run a quick scan of vulnerable files immediately afterward.

By default NAV blocks spyware, adware, and other malicious nonvirus applications. It scans e-mail going in and out of the system as well as IM file transfers. NAV is certified by ICSA and got its seventeenth consecutive Virus Bulletin 100 percent rating this year. In the latest study from AV-Test.org (www.av-test.org), it caught 100 percent of viruses and worms in the wild.

NAV's Internet Worm Protection feature blocks unsolicited inbound data packets just like Windows Firewall (which it replaces by default). It scored near perfect on Gibson Research's ShieldsUP! test. It specifically blocks known Trojans and temporarily prevents all connections from any IP address that attempts illicit access. Like Windows Firewall, NAV offers protection even before Windows has loaded. It does not attempt to block multiple e-mails sent in a short period, but it does watch for programs attempting to e-mail themselves as attachments. We still recommend users install a dedicated firewall (such as Norton Personal Firewall or ZoneAlarm Pro), but IWP does offer some degree of protection.

Like McAfee VirusScan, NAV uses the Windows Task Scheduler for scheduled full scans and looks at all file types by default. NAV scans inbound and outbound e-mail for any POP3/SMTP account. Under its default settings, detection of a virus halts all e-mail processing until the user responds. We quickly changed the settings to have the program fix problems automatically, but the program does include an option to prevent the e-mail program from timing out when it's waiting for a response.

On our test system, NAV found over 100 threats in a set of 2,000 messages. All but a handful, however, had already been neutralized by a server-side antivirus package. NAV quickly deleted the EICAR virus test file when received as an AIM file transfer. It can also filter file transfers through Yahoo! Messenger and MSN Messenger.

NAV keeps a detailed log of all blocked threats, each with a link to a detailed description on Symantec's Security Response Web site and an indication of the threat's disposition. It also reports on a variety of other security events, including incoming and outgoing connections, with IP address, port used, bytes sent, and duration.

Norton AntiVirus 2005 remains our top choice for virus protection, and the new Internet Worm Protection feature gives added security to those not using a separate firewall.