Remove Windows Setting 

If you want to change your settings on Windows Updates manualy (not from registry) you need to delete added subkey under HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU to leave only the “default” subkey.  

From <https://answers.microsoft.com/en-us/windows/forum/all/unable-to-change-windows-update-settings-some/2aafdc92-fb2e-4347-948d-ca71f87107a4?auth=1>