The last time we examined G Data's antivirus offering it impressed us with its belt and braces approach, using both the Kaspersky and Avast engines in parallel to ensure nothing slipped through the net.

That approach hasn't changed. Although the Kaspersky engine has been replaced with BitDefender, G Data intercepted 90% of our malware samples - the equal of our A List choice, Avira Premium Security Suite.

While G Data's twin-engine system may be effective, it isn't lightweight. Once installed on our test system, it continued to thrash the CPU for nine seconds after the desktop had appeared, while memory usage rose from 528MB to 810MB.

The included firewall is configurable and fairly vigilant. We were pleased to see it pop up a notification when we began probing the client's TCP ports and other vulnerabilities, although it didn't block the scan itself.

G Data also provides email integration as standard, with virus scanning and spam filtering. But there's an optional parental controls module, which lets you block specific Windows users from accessing sites containing certain terms, or from accessing the internet or using the PC outside certain time restrictions.

The blacklist isn't very smart, however (it blocked the MSN homepage for us), and there's no ability to block specific programs or monitor channels outside of the web, such as instant messaging.

In all, G Data InternetSecurity 2010 comes across as a bit of a one-trick pony, boasting excellent malware detection but little else that really stands out. The interface is clear and comprehensible, and the price isn't terrible.

But Avira has more all-round appeal and a lighter footprint. And if you really want the power of two malware engines, you can save a few dollars and buy G Data's antivirus package instead.