dcpromo error in Windows Server 2003 R2

When you try to run the Active Directory Installation Wizard on a Microsoft Windows Server 2003 R2 server, the wizard does not finish, and you may receive the following error message:

The Active Directory Installation Wizard cannot continue because the forest is not prepared for installing Windows Server 2003. Use the Adprep command-line tool to prepare both the forest and the domain. For more information about using the Adprep, see Active Directory Help.
The version of the Active Directory schema of the source forest is not compatible with the version of Active Directory on this computer.

This issue may occur when Active Directory has not been updated with the Windows Server 2003 R2 schema extensions..

To resolve this issue, run the adprep.exe /forestprep command from the Windows Server 2003 R2 installation disk 2 on the schema master. To do this, insert the Windows Server 2003 R2 installation disk 2, and then type the following command:

Drive:\CMPNENTS\R2\ADPREP\adprep.exe /forestprep

The correct version of the ADPrep.exe tool for Windows Server 2003 R2 is 5.2.3790.2075.

You can verify the operating system support level of the schema by looking at the value of the Schema Version registry subkey on a domain controller. You can find this subkey in the following location:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\NTDS\Parameters

You can also verify the operating system support level of the schema by using the Adsiedit.exe utility or the Ldp.exe utility to view the objectVersion attribute in the properties of the cn=schema,cn=configuration,dc= partition. The value of the Schema Version registry subkey and the objectVersion attribute are in decimal.

Schema Version ObjectVersion values and corresponding operating system support level

• 13=Microsoft Windows 2000
• 30=Original release version of Microsoft Windows Server 2003 and Microsoft Windows Server 2003 Service Pack 1 (SP1)
• 31=Microsoft Windows Server 2003 R2