There is some confusion in updating WSUS to WSUS SP1 on remote SQL deployments to run with (Front end and Back end) switches. WSUS SP1 update must be initiated on the backend WSUS Server first followed by the front end WSUS Server.
According to Bobbie Harder (MSFT):
You do have to run the setup package (WSUS SP1) on both the back-end Server (first run on back-end server) and then on front-end server without passing any switches. The steps which have been tested and validated should be:
1) Run the setup package on the front-end with no switches and choose to upgrade.
2) Run the setup package on the back-end with no switches and choose to upgrade.
3) ALSO, If you have migrated your WSUS server database (WMSDE) to a SQL server (local or remote) you must change the value of the following TWO registry entries before attempting to upgrade to WSUS SP1.:
- HKLM\Software\Microsoft\Update Services\Server\Setup\WmsdeInstalled, from “1” to “0“
- HKLM\Software\Microsoft\Update Services\Server\Setup\InstallType from “0x80” to “0x20“
If you are struggling with installing WSUS SP1 then feel free to post your issues on microsoft.public.windows.server.update_services