Want to protect your cyber security and still get fast solutions? Ask a secure question today.Go Premium

  • Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 1297
  • Last Modified:

Add Domain controller: first prepare the domain using "adprep/domainprep"

Hello everyone

In a environment we have a Domain controller that is Windows Server 2008 and the second DC is Windows Server 2003 R2. The actual function level of the AD was first Windows 2000 native. Now we want to add a additional DC with Windows Server 2008 R2. When I want to add him as a "additional Server in a existing domain" the message occurs "to install a domain controller into this AD Domain, you must first prepare the domain using "adprep/domainprep". After this error occurs we prepaired the domain to using Windows 2003 function level and raised  the function level successfully to Windows 2003.

After that when we want to re-add the new DC the error still occurs.

Do you know what's the problem?

Thanks for your help.
1 Solution
On your Windows 2008 R2 DVD is an executable called adprep (and adprep32 if I remember correctly).

Copy that directory to one of your DCs and run the application with the /domainprep switch. You may also have to run it with the /forestprep switch to add the server.

see below for instructions as found on the technet website:

Prepare your Active Directory® environment with Windows Server 2008 R2 updates. Before you add a domain controller that is running Windows Server 2008 R2 to an Active Directory forest or upgrade an existing domain controller to Windows Server 2008 R2, run Adprep.exe from the Windows Server 2008 R2 media on your existing domain controllers to prepare your domain and forest.

To do this, use the following procedures. If you are performing an unattended installation, perform this step before you install the operating system. Otherwise, you will need to do this after you run Setup and before you install Active Directory Domain Services.

To prepare a forest

1.Log on to the schema master as a member of the Enterprise Admins, Schema Admins, or Domain Admins group.

2.Copy the contents of the \support\adprep folder (note the new location) from the Windows Server 2008 R2 installation DVD to the schema master role holder.

3.Open a Command Prompt window, navigate to the Adprep folder, and run adprep /forestprep.

4.If you plan to install a read-only domain controller (RODC), run adprep /rodcprep.

5.Allow the operation to complete and the changes to replicate before performing the next procedure.

To prepare a domain

Perform this procedure for each domain where you want to install a domain controller that runs Windows Server 2008 R2.

1.Log on to the infrastructure master as a member of the Domain Admins group.

2.Copy the contents of the \support\adprep folder (note the new location) from the installation DVD to the infrastructure master role holder.

3.Open a Command Prompt window, navigate to the Adprep folder, and run adprep /domainprep /gpprep.

4.Allow the operation to complete and the changes to replicate.

After completing these steps, you can add domain controllers that are running Windows Server 2008 R2 to the domains you have prepared.

The adprep command extends the schema, updates default security descriptors of selected objects, and adds new directory objects as required by some applications. For more information about adprep, see http://go.microsoft.com/fwlink/?linkid=50439.

For the full page goto:

Kind regards,


you can not add windows 2008 R2 domain controller to your current domain without update the schema with windows 2008 R2.

you have to use Adprep32.exe, or Adprep.exe located in your windows 2008 R2 in  the \support\adprep folder.

In Windows Server 2008 R2, Adprep is available in a 32-bit version and a 64-bit version. The 64-bit version runs by default. If you need to run Adprep on a 32-bit computer, run the 32-bit version (Adprep32.exe).

You must run adprep from an elevated command prompt. To open an elevated command prompt, click Start, right-click Command Prompt, and then click Run as administrator.

run the following commands :

adprep /forestprep
adprep /domainprep

if you will install RODC you need to run the command below
adprep /rodcprep
Simplify Active Directory Administration

Administration of Active Directory does not have to be hard.  Too often what should be a simple task is made more difficult than it needs to be.The solution?  Hyena from SystemTools Software.  With ease-of-use as well as powerful importing and bulk updating capabilities.

Darius GhassemCommented:
axegaAuthor Commented:
there was a problem with the installed Windows 2003 R2 DC. now I demoted it to a Member Server, rerun adprep and the problem is solved. Thanks your help!!
good answer from axega, he just use what we said to him but in his words!!!!!

Featured Post

Granular recovery for Microsoft Exchange

With Veeam Explorer for Microsoft Exchange you can choose the Exchange Servers and restore points you’re interested in, and Veeam Explorer will present the contents of those mailbox stores for browsing, searching and exporting.

Tackle projects and never again get stuck behind a technical roadblock.
Join Now