There is another article that asks this question:
https://community.norton.com/en/forums/norton-cleanup-task-popups-after-installing-windows-10
...yet there is no way to respond to that article.
After spending hours on chat with the worthless entry-level techs at Norton and experiencing intense frustration trying to communicate with them, the manager finally got someone on the screen-share with us that actually knew what he was doing. Solution is below, but first, here is what is going on:
At 19, 39 and 59 minutes after each hour, a DOS windows with nothing more than CMD.EXE in the title bar would pop-up, then disappear after a couple seconds. After a year or so of having the issue, I finally spent the time to dig, and found this, which led me to understanding that it was Norton:
To see this for yourself:
1) Press WINDOWS KEY + R,
2) Type taskschd.msc and press ENTER.
3) Click on the root, "Task Scheduler (local)".
4) Change "Last 24 hours" to "Last Hour" to narrow your search.
5) From the task list, find "NortonCleanupTask" and expand it.
There, you will see the times that correspond with your DOS window pop-ups.
To fix this:
1) In the bottom-section of Task Scheduler titled "Task Status", double-click on "NortonCleanupTask".
2) Double-click "NortonCleanupTask" again to open the Triggers/Conditions edit screen.
3) Choose the "Triggers" tab.
4) Set the idle times as shown below.
5) Save and reboot.
This took care of it for me. Good luck to you all.
