Can’t log in to Windows Server 2012 after removing AD DS

active-directorywindows-server-2012-r2

As title says, I just demoted my domain controller on my Windows Server 2012. I followed this guide in doing so:

How to demote a Domain Controller in Windows Server 2012 (AD DS) | blogs.interfacett.com

But upon reboot, I can't log in using Remote Desktop with my credentials. I've tried my old and new credentials and neither work. I've even plugged a keyboard and monitor into the server, and I can't log in with my old/new password there either.

I don't want to have to reset the whole server, is there any way I could find out what the password might have been set to?

I have tried to input a blank password also.

Best Answer

the simplest way is to reset the administrator password.

You will find many way googling it.

This one should work (I even used it to reset a domain administrator password in a lab) :

Instructions

To reset the password on your Windows 2012 server, simply complete the following steps:

  • Boot from the Micrsoft Windows Server 2012 DVD
  • From the Windows Setup menu, click “Next”.
  • Select “Repair your computer”
  • Under Choose and option, click on “Troubleshoot”.
  • Under Advanced options, click “Command Prompt”.
  • At the command prompt, run the following commands:
 d:
 cd windows\system32
 ren Utilman.exe Utilman.exe.old
 copy cmd.exe Utilman.exe
  • Close the command prompt and then click “Continue”.
  • The server should now boot and present the logon screen.
  • Here click Windows Key + U.
  • At the prompt you can now change the password, by typing the following command:
net user administrator Password123

This will set the password for the Administrator user to be Password123 (case sensitive).

Closing the command prompt, you should now be able to log back onto the server using the password you have provided in the last step.

Cleanup Steps

Once you have verified you can log on to the server you will have repeat the steps above and boot using the Windows Server 2008 DVD/ISO and run the command prompt again.

Restart your server and once again, boot from the Micrsoft Windows Server 2012 DVD From the Windows Setup menu, click “Next”. Select “Repair your computer” Under Choose and option, click on “Troubleshoot”. Under Advanced options, click “Command Prompt”. At the command prompt, run the following commands: d: cd windows\system32 ren utilman.exe utilman.exe.new copy utilman.exe.old utilman.exe

Close the command prompt and then click “Continue”.

You should be back up and running as if nothing ever happened.

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