writes "PC World has a story reporting that Microsoft's Windows Live OneCare came in dead last out of a group of 17 antivirus programs tested against hundreds of thousands of pieces of malware. The report of an Austrian antivirus researcher was released at the AV Comparatives Web site this week. Several free AV products were included in the test as well."
While the top dog was able to find 99.5% of the malicious code, OneCare clocked in at 82.4%. Of course, there's no metric for the severity of the malware in the 17% gap.