Microsoft Windows Live OneCare was already struggling in the credibility stakes after failing to pass the Virus Bulletin VB100 certification tests as I reported here last month.

Talk about kicking a wounded animal, now the results of the latest, and much respected, av-comparatives are in, and do no make for comfortable reading if you happen to be Microsoft.

Security researcher Andreas Clementi conducted in-depth testing of 17 anti-virus scanners, subjecting them to no less than 497,608 items of malware during the process. This is not, by any stretch of the imagination, a test to be dismissed as insignificant. It is the real deal, which is why the results are so devastating for Microsoft. Of those 17 products, including entries from all the major vendors in the marketplace, Windows Live OneCare came last. Worse yet, it came last by quite some margin.

Indeed, only it and the little known Dr Web scanner failed to reach an overall detection rating of 90% and whereas Dr Web only just failed, with 89.27%, OneCare managed a really very poor 82.4%. Compare this with G-DATA AVK leading the test on 99.45%, F-Secure 97.91%, Kaspersky 87.89% and even arch-rivals Symantec Norton AV with 96.83%.

So bad was the OneCare result, in fact, that it didn’t actually make the cut for inclusion in the evaluation process so is unlikely to even appear in the next set of tests in August. To reach the lowest grade of certification, standard, a product needs to hit 85%. Then again, perhaps for Microsoft it will be a relief if it doesn’t as no news will be good news for a change.