I do not mind the auto-download of updates but I wish I could control the update installation process like I could on Win 8. Regardless, I needed to reboot and only then did I realize that an update was being installed. The message "do not turn off computer" was displayed for about 10 minutes before I elected to remove the SP3 from the MS dock. Immediately upon removal, miraculously, the update began to complete as evidenced by the display of a quickly increasing progress percentage. No harm, no foul but a little annoyed nonetheless.
I moved your post to the Windows 10 section. You can get back that same level of update control by following these instructions. https://4sysops.com/archives/disable-windows-update-in-windows-10/