Microsoft has updated the System Update Readiness Tool

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. This tool checks your computer for such inconsistencies and tries to resolve issues if found.

System Update Readiness Tool for Windows 7 for x64-based Systems (KB947821) [February 2013]
System Update Readiness Tool for Windows 7 (KB947821) [February 2013]
System Update Readiness Tool for Windows Server 2008 R2 for Itanium-based Systems (KB947821) [February 2013]
System Update Readiness Tool for Windows Server 2008 for Itanium-based Systems (KB947821) [February 2013]
System Update Readiness Tool for Windows Vista for x64-based systems (KB947821) [February 2013]
System Update Readiness Tool for Windows Server 2008 x64 Edition (KB947821) [February 2013]