Avoid Win 10 to hijack older version OS

Recently I power on my pc and go to buy breakfast, When I returned I found the Win 10 update is processing. From previous experience, I power off system to stop windows update then power on again. The win 7 desktop is returned but win 10 update icon is still on the task bar. I google and find "never 10" (https://www.grc.com/never10.htm  )  Download the file and run the file.

First, I removed win 10 files folder from system.

second, click " Disable Win10 update" then reboot system. The win 10 update icon is gone.