Reset the Domain Admin password in Windows Server 2012 R2

To reset the Domain Admin password in Windows Server 2012 R2 you do the following.

    Shutdown the domain controller (VM most likely).
    Boot on the Windows Server 2012 R2 installation media or any other WinPE boot media.
    Open a command prompt; Shift + F10 if using the installation media.
    Rename the C:\Windows\System32\utilman.exe file to utilman.bak.
    Copy the C:\Windows\System32\cmd.exe to utilman.exe.
    Start the domain controller again.
    At the login screen, press Windows + U or click the “Easy of Access” button.
    Type in: net user administrator newpass123!
    Exit the command prompt, and login with the new password.