In the process of installing software, it may take a lot of time if there are many software to be deployed by MDT.
So , in this case, the Windows itself may automatically get and install updates from Windows Update site via internet, a popup coming out to show a time count down of automatic restartof Windows Update. I must click on "No" to prevent reboot.
If this is an unattended senario, the automatic reboot of Windows Update may interrupt the normal deployment.
How to just only suppress the reboot , if possible, do not disable Windows Update.