Unlike most other security suites (whose origins tend to be in the antivirus market), CheckPoint's ZoneAlarm started out as a firewall and expanded from there. And it shows.

ZoneAlarm Internet Security Suite has a feature-rich firewall, to which it has added the impressive Kaspersky antivirus engine for malware detection and removal.

Unfortunately, ZoneAlarm Internet Security Suite lacks the extensive scan options and the smooth interface of Kaspersky's own software. In addition, the antivirus and anti-spyware interface has only bare-bones configuration options.

To be fair to ZoneAlarm Internet Security Suite, it's still struggling with Vista compatibility. Working under Microsoft's latest OS, the ZoneAlarm antivirus scanner doesn't scan e-mail traffic or instant messaging communications for malware.

CheckPoint claims this is by design, but we can't see the benefit of refraining from scanning e-mail traffic. The Vista ZoneAlarm Internet Security Suite also loses the parental controls available in the XP version, as well as protection for sensitive data and blocking of known spyware Web sites. The suite lacks a Web antiphishing feature in both its XP and Vista versions.

For the firewall, ZoneAlarm Internet Security Suite offers the most features and options of pretty much any suite available. It comes with an excellent installation wizard, and a training mode automatically bumps up to maximum protection after learning about your programs.

Even at its "maximum protect" setting, the ZoneAlarm Internet Security Suite firewall will check against a central database of known programs before bugging you to decide whether a new program can connect to the Internet.

There were problems in testing though, and ZoneAlarm Internet Security Suite didn't entirely protect our sample PC from an outside scan. Neither did it entirely hide the closed channels. According to AV-Test.org, the XP version doesn't exhibit this problem.

Backed up by Kaspersky's engine, ZoneAlarm Internet Security Suite's malware detection rate was high -- around 96 per cent -- but it did lag on scan speed. Indeed, at just 3.62 megabytes per second (MBps), it produced one of the slowest test times of any package.

ZoneAlarm Internet Security Suite's options and interface for antivirus scanning are anaemic. You can't decide whether to scan within archives for a user-started scan or for an automatic, on-access scan. You can't decide much of anything else, either.