AV-Comparatives, a project in Austria overseen by security researcher Andreas Clementi, published the antivirus comparison report, which also looked at products from Symantec Corp., McAfee Inc., Kaspersky Lab Ltd., BitDefender, Fortinet Inc., F-Secure Corp. and several other antivirus products from smaller vendors.

In detecting Windows viruses, worms, macros, scripts and other OS threats, Microsoft ranked last out of the 15 vendors tested, detecting them 91 percent of the time. G Data Software AG's Anti-Virus Kit (AVK) ranked first with 99.6 percent detection, while products from three vendors-- Kaspersky Anti-Virus, MicroWorld Technologies Inc.'s eScan and F-Secure Anti-Virus-- tied for second with 99 percent detection. TrustPort Antivirus Workstation from AED Ltd. came in third with 98.9 percent detection.

In preventing intrusion through backdoors, Trojans and in other malware detection, Windows OneCare also ranked last out of 13 vendors, with 79.6 percent detection. TrustPort came in first at 99.5 percent detection; AVK came in second with 99.4 percent detection; and AVIRA GmbH's AntiVir Personal Edition Premium came in third with 98.9 percent detection.

If ranking low in its rates of malware and virus detection isn't enough to irk users, a recent update to the product has been quarantining the Outlook.PST file, which stores mail in Outlook and Outlook Express, users reported recently on a Microsoft Windows user form.

"This is the most unacceptable act Microsoft has ever committed," groused one user, with the log-in TG4752, on the forum. "I run a small business and I am screwed. I have no way to respond to e-mails because I made the mistake of trusting Microsoft... and all of my e-mails and contacts are gone."

Microsoft confirmed the problem and has patched it.