This procedure describes how to promote a new domain controller using the backup of
the same Active Directory database without the need to replicate NTDS.DIT file over the network.

1. Create a backup of an existing Windows Server 2008 domain controller in the domain the new server will go in.
you can do it using Backup Exec, Arcserv or ntdsutil utility.

2. use Server Manager to add the Active Directory Domain Services.
3. run dcpromo with the /adv switch from a command line to start dcpromo wizard.

4. select "Existing Forest"  > Add a Domain Controller to an existing domain and click Next.

5. enter the name of the domain to which you are adding the DC In the Network Credentials screen and Click Next.

6. select the domain to which you want to add the DC and  click Next.

7. select the site that the new DC should be part of and click Next.

8. select one or all of the following configuration options for the new DC: DNS Server, Global Catalog, and Read-Only Domain Controller and Click Next.

9. select the "Replicate data from media at the following location" option.
10. browse to the location of the backup and Click Next.

11. select the existing DC that will transmit replicate information or mark"Let the wizard choose an appropriate domain controller" and Click Next.

12. modify the default location of the Active Directory database files, logfiles, and SYSVOL if needed and click Next.

13. enter and confirm a recovery password for Active Directory and click Next.

14. Click Next to begin dc promotion.
15. restart the server.