While forgetting your domain admin password is not really something you should do you may come across a server that you don’t know the domain administrator password for this video will help you.
You will need a Windows Server installation disk to complete these steps.
Boot to a windows server 2012 r2 CD and hold shift F12 then run the bottom two commands
- MOVE C:\Windows\System32\Utilman.exe C:\Windows\System32\Utilman.exe.bak
- COPY C:\Windows\System32\cmd.exe C:\Windows\System32\Utilman.exe
Once that is done you can reboot the server and click on the “Ease of Access” button. This will give you a command prompt where you can reset the domain admin password using the net user command:
net user administrator *
It will then prompt you for the new password.
Type in the new password that you want and hit enter.
Now you have reset your domain administrator password and you can log into the server.