WSUS setting

I set up Group policy so that all PC access to WSUS server to update .
I thought the configuration was successful.
On WSUS server, all pc is appear and I can attach some update file to all pc.
This windows update is supposed to be done without any user's confirmation,
when shutdown and starting , all windows update would be installed.

However, I noticed that each user can select update from windows update .
each user has only thier ordianary user's permission.


I am not sure reason why user can select update from the update list.
I don't want not to allow users to select some update.
without any confirmation, automatically, update should be done.

In order to do this, what kind of point should I check ?
important things are missing ?