ZoneAlarm Extreme Security is, as you might expect from the "Extreme" tag, an unusually full-featured security suite.

It includes an excellent firewall, of course, which manages to control your applications without the hassle of endless alerts. The suite's strong on-demand and real-time antivirus protection is based on highly-rated Kaspersky technology, and the spam filter protects your Outlook, Outlook Express and Windows Mail inbox.

And browsing protection sees ZoneAlarm Extreme Security monitoring the sites you attempt to visit, and the files you download, warning you about any that appear to be dangerous.

But there's also much more. Like solid Parental Controls, based on Net Nanny; an online backup tool with 2GB of free server space; browser virtualisation, which keeps any malware away from your system; a Registry-cleaning PC Tuneup module, private browsing, keylogger jamming, and more.

Perhaps the best example of the extra power on offer here is the Identity Protection module. Like many other suites, it allows you to enter personal information - addresses, credit card details, phone numbers and so on - and then ensures they can't leave your PC without permission. But it also offers American users a free one year subscription to Identity Guard, which provides daily credit record monitoring, email alerts of any activity, and free phone assistance if this reveals anything suspect.

There's a price to pay for this, of course, and Extreme Security is the most expensive product in the ZoneAlarm range. If you don't need quite so much power then ZoneAlarm Internet Security Suite drops Registry cleaning, virtual and private browsing, and keylogger jamming, and is $10 cheaper. And if you don't need the parental controls or spam filter then opting for ZoneAlarm Antivirus + Firewall will save you another $10. Find out more and compare the various editions at the ZoneAlarm site.