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Removing a Domain Controller from a Domain

  • Articolo

Applies To: Windows Server 2008, Windows Server 2008 R2

The procedures in this section describe the methods for removing a Windows Server 2008 or Windows Server 2008 R2 domain controller from a domain:

  • Removing a domain controller by using the Windows interface

  • Removing a domain controller by using an answer file

  • Removing a domain controller by entering unattended installation parameters at the command line

After AD DS is removed, the DNS server role remains installed and running if it was previously installed on the domain controller. But any Active Directory–integrated DNS zones that were installed are removed. By default, the AD DS removal process also attempts to remove the Domain Name System (DNS) delegations for the zones that point to the domain controller.

If the DNS server no longer serves any purpose after you remove AD DS, use Remove Roles Wizard to remove DNS server role. If you remove the DNS server role, you must reconfigure any DHCP scopes and DNS clients that resolved against this DNS server to use a suitable alternative (typically, another DNS server running on a domain controller within the same domain).

Removing a domain controller by using the Windows interface

You can use the Active Directory Domain Services Installation Wizard to remove a domain controller from an existing domain.

Administrative credentials

To perform this procedure, you must be a member of the Domain Admins group in the domain.

To remove a domain controller by using the Windows interface

  1. Click Start, click Run, type dcpromo, and then press ENTER.

  2. On the Welcome to the Active Directory Domain Services Installation Wizard page, click Next.

  3. If the domain controller is a global catalog server, a message appears to warn you about the effect of removing a global catalog server from the environment. Click OK to continue.

  4. On the Delete the Domain page, make no selection, and then click Next.

  5. If the domain controller has application directory partitions, on the Application Directory Partitions page, view the application directory partitions in the list, and then remove or retain application directory partitions, as follows:

    • If you do not want to retain any application directory partitions that are stored on the domain controller, click Next.

    • If you want to retain an application directory partition that an application has created on the domain controller, use the application that created the partition to remove it, and then click Refresh to update the list.

  6. If the Confirm Deletion page appears, select the option to delete all application directory partitions on the domain controller, and then click Next.

  7. On the Remove DNS Delegation page, verify that the Delete the DNS delegations pointing to this server check box is selected, and then click Next.

  8. If necessary, enter administrative credentials for the server that hosts the DNS zones that contain the DNS delegation for this server, and then click OK.

  9. On the Administrator Password page, type and confirm a secure password for the local Administrator account, and then click Next.

  10. On the Summary page, to save the settings that you selected to an answer file that you can use to automate subsequent operations in Active Directory Domain Services (AD DS), click Export settings. Type a name for your answer file, and then click Save. Review your selections, and then click Next to remove AD DS.

  11. On the Completing the Active Directory Domain Services Installation Wizard page, click Finish.

  12. You can either select the Reboot on completion check box to have the server restart automatically or you can restart the server to complete the AD DS removal when you are prompted to do so.

  13. Open Server Manager. Click Start, point to Administrative Tools, and then click Server Manager.

  14. In Roles Summary, click Remove Roles.

  15. If necessary, review the information on the Before You Begin page, and then click Next.

  16. On the Remove Server Roles page, clear the Active Directory Domain Services check box, and then click Next.

  17. On the Confirm Removal Selections page, click Remove.

  18. On the Removal Results page, click Close, and then click Yes to restart the server.

Removing a domain controller by using an answer file

To remove a domain controller in a domain where other domain controllers exist requires only Domain Admin credentials. You can also create the password for the local Administrator account for the member server. If you do not specify the password in the answer file, the administrator password is blank.

If you are removing AD DS permanently, uninstall the AD DS server role binaries from the server after you remove AD DS from the domain controller. To remove the AD DS server role binaries, use the dcpromo /uninstallbinaries command.

Administrative credentials

To perform this procedure, you can use any account that has Read and Write credentials for the text editor application.

To create an answer file for removing a domain controller

  1. Open Notepad or any text editor.

  2. On the first line, type [DCINSTALL], and then press ENTER.

  3. Create the following entries, one entry on each line. For a complete list of parameters for removing AD DS, see Demotion Operation or type dcpromo /?:Demotion at a command line.

    username=<administrative account in the domain>

    userdomain=<domain name of the administrative account>

    password=<password for the account in UserName>

    administratorpassword=<local administrator password for the server>

    removeapplicationpartitions=yes

    removeDNSDelegation=yes

    DNSDelegationUserName=<DNS server administrative account for the DNS zone that contains the DNS delegation>

    DNSDelegationPassword=<Password for the DNS server administrative account>

  4. Save the answer file to the location on the installation server from which it is to be called by dcpromo, or save the file to a network shared folder or removable media for distribution.

Administrative credentials

To remove a domain controller, you must be a member of the Domain Admins group.

To remove a domain controller by using an answer file

  • At an elevated command prompt, type the following command, and then press ENTER:

    dcpromo /unattend:"<path to the answer file>"

Removing a domain controller by entering unattended installation parameters at the command line

You can run dcpromo /unattend command on a domain controller to perform an unattended removal of AD DS. If you are removing AD DS permanently, uninstall the AD DS server role binaries from the server after you remove AD DS from the domain controller. To remove the AD DS server role binaries, use the dcpromo /uninstallbinaries command.

For a complete list of parameters for removing AD DS, see Demotion Operationor type dcpromo /?:Demotion at a command line.

To remove a domain controller by using the command line

  • At an elevated command prompt, type the following command, and then press ENTER:

    dcpromo /unattend /username:<domain admin> /userdomain:<domain> /password:<DA password> /administratorpassword:<local admin password>

    Where:

    • domain admin is the name of an account that is a member of the Domain Admins group.

    • domain is the name of the domain for the domain controller.

    • DA password is the password for the account that is a member of the Domain Admins group.

    • local admin password is the password that will be used for the local administrator account on the server after AD DS is removed.

    The following example removes a domain controller from a domain named contoso.com, removes the AD DS server role binaries, and sets the local administrator password to p@$$w0rd:

    dcpromo /unattend /username:DA1 /userdomain: contoso.com /password: DA1_password /administratorpassword: p@$$w0rd