For WSUS users, the Standalone Package of the Service Pack and its prerequisites will be available on the MU Catalog Tuesday March 25 but before that, there are a few things to take into consideration:
- This process applies to WSUS 3.0 RTM and SP1 servers only.
- If you are running your WSUS server on a Windows 2003 Server, you will first need to download and install the WinTrustVerify update (KB 938759) on that server.
Read the complete article : WSUS Product Team Blog