we have our WSUS server and we have these GPO settings:
Delay Restart for scheduled installations Disabled
Do not adjust default option to 'Install Updates and Shut Down' in Shut Down Windows dialog box Disabled
Do not display 'Install Updates and Shut Down' option in Shut Down Windows dialog box Disabled
No auto-restart for scheduled Automatic Updates installations Enabled
Re-prompt for restart with scheduled installations Enabled
but our servers get rebooted whenever the updates are installed, and we don't want that to happen.