WSUS is not downloading Malicious Software Removal Tool (MSRT). Why?
The Malicious Software Removal Tool is in the Update Rollup category. Make sure you have that selected Update Rollups to synchronize with MU. Update Rollups classification is not selected by default, you must select “Update Rollups” under “Update classifications” to synchronize with MU.
When you select “Update Rollups” under “Update classifications”, you might notice other roll-up packages (like Update Rollup for Windows XP e.t.c) are seen in WSUSAdmin console. Note that only Metadata for those rollups will be downloaded and the update files will not be downloaded unless you approve them for “Install”.
How do I verify whether the MSRT removal tool has run on a client computer?
You can examine the value data for following registry entry to verify the execution of the tool.
Entry name: Version <GUID> (d0f3ea76-76c8-4287-8cdf-bdfee5e446ec)
Every time the tool is run, independent of the results of the execution, the tool will record a GUID to the registry to indicate that it has been executed. You can find the list of version GUID’s on http://support.microsoft.com/?kbid=891716&SD=tech#E2ACAAA