Maybe the way to block it is still: https://support.microsoft.com/en-us/kb/3080351 Subkey: HKLM\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate DWORD value: DisableOSUpgrade = 1 The MSFT decision to perform forced updates is covered, for example, by Extreme Tech, February 2: "Look out: Microsoft shifts Windows 10 to ‘Recommended’ update, automatic download" http://www.extremetech.com/computing/222326-look-out-micro…
That should get the right people involved for sticking the boots in.