wuauclt.exe has these parameters (not all are verified. gleaned from various posts on the web.)
/configlist - lists WUAUCLT configuration./installAUclient - Install the correct AU client by force
/installAUclientFromMicrosoft - This option causes the system to contact either the confiugred WSUS server, or Microsoft's WU server, and to reinstall forefully the latest version of the AU client.
/clearlogfile - clears the client update log file
/clearandsavelogfile - saves the current client update log file to a named file, then clears the update log.
/downloadnow - initiates an immiate downoad of any requried update using BITS
/downloanowfast - initiates an initiates an immiate downoad of any requried update using HTTP.
/stopdownload - stops any AU updates being downloaded (either using HTTP, or BITS).
/TestWSUSServer - checks connection with configured WU Server