I beg to differ. Microsoft used underhand tactics to force Windows 10 on users, where at one point closing the upgrade prompt window by clicking the X at the top-right was taken as permission to install. The difference between Windows 8.1 and 10 was marked, particularly because when Windows 10 was first released it was extremely buggy, and the in-place installation broke swathes of drivers, programs and lost settings. (At least, this was my experience as the person called to fix such problems).