Install an Additional Domain Controller by Using an Answer File
Applies To: Windows Server 2008, Windows Server 2008 R2
You can use this procedure to install an additional domain controller in an existing domain. To perform this procedure, you must have created an answer file. You can create an answer file automatically when you install a domain controller using the Active Directory Domain Services Installation Wizard by selecting the option to export the installation information to a file. For information about creating an answer file manually, see Create an Answer File for Unattended Domain Controller Installation.
You can also use an answer file to create a new domain.
After you create the answer file, use the following procedure to perform the unattended installation. You can use this procedure to install Active Directory Domain Services (AD DS) on either a full installation of Windows Server 2008 or a Server Core installation of Windows Server 2008.
Membership in Domain Admins, or equivalent, is the minimum required to complete this procedure. Review details about using the appropriate accounts and group memberships at Local and Domain Default Groups (http://go.microsoft.com/fwlink/?LinkId=83477).
To install a new domain controller by using an answer file
Open a Command Prompt as an administrator: On the Start menu, right-click Command Prompt, and then click Run as administrator. If the User Account Control dialog box appears, provide Domain Admins credentials, if required, and then click Continue.
At the command prompt, type the following command, and then press ENTER:
dcpromo /unattend:"<path to the answer file>"