There were choices to or not to accept automatic updates in a bunch of different questions when the computer was setting itself up after I made it go back to factory settings.
It had nothing to do with Windows, and everything to do with those questions. However, the first time we set it up, those questions weren't there, so someone, somewhere, had already gone through those choices BEFORE we even turned the computer on.
Once we turned the computer on, and finished with the pre-setup-questions, it just automatically decided it was okay to update to Windows 10.