After demoting a Server 2008 domain to its standard config the Administrator's password is no longer valid. I can't log on. How do I fix this?

Hi, I would like to confirm whether you run dcpromo to demote a 2008 DC, after that, you cannot log on 2008 PC with the administrator account. Did you receive any error message? If so and if it is still a member server, can you log on with the domain admin account? Can you access this PC via network? During the demote process, we need to set the password for the administrator account on the server after Active Directory is removed. Did you receive any troubles? Did you enter this password? Please go to AD Users and Configuration on your existing DC, check whether this 2008 PC shows as a DC or Computer. If it still shows as DC, please manually deleted this PC from the Domain Controllers group. After restarting, please check the results. If the issue persists, it seemed that the 2008 DC did not demote properly, please run a metadata cleanup. For more information, please refer to the following support article: http://support.microsoft.com/kb/216498 Thanks. NinaThis posting is provided "AS IS" with no warranties, and confers no rights.

This is a triky thing. But i know Windows Password Key Enterprise can help you remove or reset Windows Server 2008 domain password. You can see the article which shows how to do below http://www.blog.lostwindowspassword.com/how-to-reset-windows-server-2008-password-2/ Windows Password Recovery