Disable and Stop Restart or Reboot After Installing Windows Update

Set Automatic Updates to “Download updates for me, but let me choose when to install them”. Go to Control Panel > System > Automatic Updates tab.
Disable auto restart for automatic updates in Group Policy..
Disable Permanently – Using Group Policy

1. Head to Start >> Run >> type gpedit.msc >> hit Enter
2. Above step will open group policy editor
3. Now go to Computer Configuration >> Administrative Templates >> Windows Components >> Windows Update
4. On the right hand side pane, double click on No auto-restart with logged on users for scheduled automatic updates installations and enable it