A software security update released by Microsoft nine days ago to fix a flaw in Windows 2000 has been reissued after the company determined that the original patch didn't completely fix a security problem.

The reissued patch download should be installed by users of all Windows 2000, even by those who previously installed the original patch from 10 October, the company said.

The service bulletin describing the problem, MS06-061, was aimed at repairing vulnerabilities in Microsoft XML core services that could allow remote code execution by attackers if uncorrected. Other Windows XP and Server OSes (operating systems) are also described in the service bulletin, but they are being repaired properly by the original patch and are not affected by the reissued advisory, the company said.

The rereleased patch, which is rated as 'critical' by Microsoft, does not need to be reinstalled by any other Windows users.