i get this error: “WindowsUpdate_00000646”

Security Update for the 2007 Microsoft Office System (KB976321)

Installation date: ‎13/‎05/‎2010 1:50 PM

Installation status: Failed

Error details: Code 646

Update type: Important

A security vulnerability exists in the 2007 Microsoft Office System that could allow arbitrary code to run when a maliciously modified file is opened. This update resolves that vulnerability.

More information:
http://support.microsoft.com/kb/976321

Help and Support:
http://support.microsoft.com/?LN=en-us