So you are saying that Windows is resetting the permissions on the folder with your save games, or its parent folder? I don't know of anything in Windows that would do that, so I would be concerned that you have some app that is doing this. What is the path to the folder?
C:/Program Files (x86)/Sheltered/saves/
That folder would keep locking as read only, and it's contents as well, despite all the ownership permissions being correct.
It couldn't have been another app doing it - it was the only thing installed on the laptop other than Windows itself at the time.

If you look up read only bug, there is a fair amount out there on it now. Never happened on my computers that were Win7 upgrades, just this Win 10 one.