How to defeat shared themes?

[Pogo]

I have different, distinctive wallpapers for the themes on my Win 8.1 desktop & Win 10 laptop. Every so often one will sync with the other. (Needless to say, they are both on our home network.) No pattern, just random annoyance. No matter how often I "personalize" and delete the synced theme & go back to the preferred theme for each computer, after a while it happens all over again. How to eliminate this annoyance?

 

[Pogo]

Finally seem

I have different, distinctive wallpapers for the themes on my Win 8.1 desktop & Win 10 laptop. Every so often one will sync with the other. (Needless to say, they are both on our home network.) No pattern, just random annoyance. No matter how often I "personalize" and delete the synced theme & go back to the preferred theme for each computer, after a while it happens all over again. How to eliminate this annoyance?

Finally seem to have found the answer. In Win 10, under personalize, select themes then type 'synch' in the search box. Among options that come up is turn synched themes on or off. (This option does not show in Win 8.1.)