Microsoft has released the May 2011 update of the System Update Readiness Tool



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