How to block the Windows 10 upgrade

Maury was one of several readers who complained about the Windows 10 upgrade starting without user permission. I have been hearing a lot about this recently. Another reader got to the point where he was scared to boot, assuming that the installation would happen right away. Even I was a victim. Windows told me I needed to shut down the PC for an update. When I shut down and rebooted, no update happened, but Windows continued to tell me that I needed to shut down. Some detective work clued me in ...