- Boot the server from Windows Server 2016 Installation DVD
- SHIFT + F10 when Setup screen is loaded
- Execute the following (switch Ease of Access with cmd)
c: cd windows\system32 ren Utilman.exe Utilman.exe.original copy cmd.exe Utilman.exe shutdown -r -t 0
- Remove DVD and press Windows Key+U on Welcome screen.
- Set a new password
net user Administrator NewPassword123
- Rename Utilman.exe.original back to Utilman.exe