Microsoft has made a free beta of Windows OneCare open to the general public. And while you might be tempted to give it a spin, think twice before taking the plunge. First and foremost, Windows OneCare won't work with any other firewall than the built-in and less protective Windows XP firewall, it won't work with any other antivirus software on the system, and it appears to suffer from the same problems that beset earlier Microsoft attempts to get into the antivirus business - poor response to new threats.

I checked Windows OneCare against a newer variant of the Goldun keylogger Trojan as well as a recent variant of the Mitglieder backdoor Trojan family. In both cases, Windows OneCare reported that the files were not infected. Conversely, traditional antivirus protection from McAfee, Symantec, Panda, Trend, and dozens of other antivirus software vendors were able to detect the infections despite the threats being relatively new.

Being behind the curve in detecting newer threats may be only one of Windows OneCare's shortcomings. Many of today's viruses travel via password protected zips. But Microsoft's Windows OneCare can't scan inside password protected zips. Windows Firewall is also trivial for virus writers to defeat - in fact, most of today's malicious software routinely disable the Windows XP firewall as part of their infection process.

Unless and until Microsoft improves the product - and allows it to play nice with the more secure third-party firewalls - Windows OneCare might best be suited for users who simply don't care. If you are like most of us and security is a concern, stick with tried and true antivirus software from reputable, reliable antivirus and firewall vendors.