Loading ...The two computers are talking to each other,via bluetooth or over yr WiFi.
Shut down the PC and delete what u don’t need on the Laptop…..But make a Copy of what u need on the PC on a thumb drive, in case it gets the idea that the Laptop is boss.
But if the email is Yahoo, then I doubt the data is on either Computer, it is on Yahoo’s cloud, which is why when u delete on 1 it is the same on the other.