You seem to have a not uncommon problem with this KB article. Also 64bit systems have been worse than 32bit.
The best solutions that I can find are to run sfc /scannow
and to use the update tool supplied by M/soft first (see link below)
System Update Readiness Tool for Windows 7 (KB947821) [August 2011]
This tool is being offered because an inconsistency was found in the Windows servicing store which may prevent the successful installation of future updates, service packs, and software.http://www.microsoft.com/download/en/details.aspx?id=3132