To reset the Administrator password on your Windows server 2012 installation, you’ll need to do the following:
Boot from the Microsoft Windows Server 2012 DVD
- From the Windows setup menu, click “Next”
- Select “Repair your computer”
- Click on “Troubleshoot”
- Under Advanced options, click “Command Prompt”
- Type “diskpart” and hit Enter
- Type “list volume” and hit Enter. This will show you your (current) drive letter allocated to the drive where Windows is installed. Note – if you don’t see any volumes listed and this is the first boot cycle for a new Server 2012 installation, then I have seen this on a few HP servers and you’ll need to go and run the setup again from within the Intelligent Provisioning area.
- Make a note of the drive letter and type “exit” then press enter to leave diskpart (but stay in the command prompt window)
- Presuming the letter is d, then type “d:” and press enter to change to this drive
- Now type “cd Windows\system32” and press enter which will take you into the system32 folder
- Type “ren Utilman.exe Utilman.bak” and press enter
- Type “copy cmd.exe Utilman.exe” and press enter
- Close the command prompt and then click “Continue”
- The server should now reboot to the logon screen. Press the Windows key + u to open a command prompt
- At the prompt you can change the password by typing “net user administrator xyz” where xyz is your new super-secure password!
- Now, for security we must do one last thing. Once we are back in Windows, open Explorer, navigate to Windows\system32 and rename Utilman.bak to Utilman.exe
Hopefully this gets you out of a sticky situation, leave me a comment if it has helped.