Microsoft has released the August 2011 issue of their 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.

System Update Readiness Tool for Windows Server 2008 R2 for Itanium-based Systems (KB947821) [August 2011]
System Update Readiness Tool for Windows Vista for x64-based Systems (KB947821) [August 2011]
System Update Readiness Tool for Windows Server 2008 R2 x64 Edition (KB947821) [August 2011]
System Update Readiness Tool for Windows Server 2008 for Itanium-based Systems (KB947821) [August 2011]
System Update Readiness Tool for Windows 7 (KB947821) [August 2011]
System Update Readiness Tool for Windows 7 for x64-based Systems (KB947821) [August 2011]
System Update Readiness Tool for Windows Server 2008 x64 Edition (KB947821) [August 2011]
System Update Readiness Tool for Windows Server 2008 (KB947821) [August 2011]
System Update Readiness Tool for Windows Vista (KB947821) [August 2011]