Windows Automatic Updates most if the time requires a restart after updating your computer with latest updates/patches. This would display the following dialog Automatic Updates dialog box.
And if you select Restart later option, you would still be prompted with this dialog box after every 15 minutes. This would annoy most of the users and it is a waste of time. But you can disable or turn off this message by stopping the Automatic Updates services.
To disable windows automatic updates restart now notification, click on the Start button –> Control Panel –> Administrative Tools –> Services. In Services windows, navigate to Automatic Updates service and right click and select stop from the menu list. This would stop the service and the users will not be prompted with Automatic Updates Restart notification.