Windows update has been an important necessity to address the potential threads. Meanwhile, automatic update usually asks the user permission to automatically restart the computer. The annoying message appears in the following image:

There is a simple way to stop the annoying this message box.

To stop the message box to keep appearing, you can open command prompt by pressing Windows+R keys and typing cmd. And then,  type sc stop wuauserv. The command will automatically stop the nagging automatic restart message box. And, you can continue working with your computer and restart it anytime you want.