Microsoft's Windows Live OneCare security service has passed the Virus Bulletin VB100 security test. 

The test requires security products to detect 100 per cent of the threats in a sample, which uses a collection of all known malware samples currently in use by attackers.

After passing in June 2006, OneCare failed the test in February when it caught 99.91 per cent of the threats.  

The public failure, combined with lacklustre results  in a test by AV Comparatives, prompted Microsoft to promise users that it would bring the security application up to snuff.  

Microsoft has pointed out that OneCare passed tests by West Coast Labs and ICSA Labs. The next AV Comparatives test is scheduled for August. 

"These accolades are a strong endorsement of OneCare's powerful anti-malware tools and mean that OneCare protects customers from known threats on the market today," OneCare lead product manager Gina Narkunas wrote on the Windows Live Spaces blog.