Another independent test of Microsoft's OneCare anti-malware suite will make grim reading in Redmond.
OneCare came last in a survey of 17 security software packages, picking up only 82.4 per cent of the 500,000 pieces of malware used in the test. All but one of the other packages scored over 90 per cent.
"Microsoft OneCare performed very low in the test and did not reach the minimum requirements for participation," said the report from independent testing site AV Comparatives. "Its inclusion in future tests this year will have to be re-evaluated."
OneCare performed particularly badly in detecting Trojans and backdoors, picking up only 79.6 per cent of attacks, and the package finished last in all three detection tests.
The overall winner of the group test was G Data's AntiVirusKit, which detected 99.45 per cent of all threats.
Most of the other top five packages use multiple scanning engines to assess threats.