To update your domain, follow these steps:
- Install Windows Server 2012.
- Run the Adprep.exe that is included on the Windows Server 2012 installation media in the following location: \support\adprep
- Use the arguments that you tried to use when you encountered the error that is described in the "Symptoms" section. For example, use the following arguments:
Windows Server 2012 Adprep.exe also removes the requirement to join a domain. You can use the /Forest, /Domain, /Userdomain, and /Password arguments to remotely update forests and domains even from a workgroup as long as you have the correct Domain Name System (DNS) name resolution. Also, just installing and configuring the first Windows Server 2012 domain controller into a forest runs the preparation process automatically, and in this scenario, you do not have to use adprep.exe.