Active Directory/Documentation/Manipulate Client Behavior Using Command-line Options
There are two documented command-line options used for manipulating Automatic Updates behavior. These options are helpful for testing and troubleshooting client computers. For comprehensive troubleshooting information for problems with both the WSUS server and client computers, see the Microsoft Windows Server Update Services 3.0 Operations Guide at http://go.microsoft.com/fwlink/?LinkId=81072.
Sends all queued reporting events to the server asynchronously.
Because waiting for detection to start can be a time-consuming process, an option has been added to allow you to initiate detection right away. On one of the computers with the new Automatic Update client installed, run the following command at the command prompt:
WSUS uses a cookie on client computers to store various types of information, including computer group membership when client-side targeting is used. By default, this cookie expires an hour after WSUS creates it. If you are using client-side targeting and change group membership, use this option in combination with detectnow to expire the cookie, initiate detection, and have WSUS update computer group membership.
Note that when combining parameters, you can use them only in the order specified as follows:
wuauclt.exe /resetauthorization /detectnow