This is the general procedure for migrating domain controllers:
- Install the new server and join it to the domain.
- Promote it to Domain Controller (
dcpromo /adv). Make sure that the
Global Catalog option is selected.
- Transfer all FSMO roles from existing DC to new DC (
netdom query fsmo will show you which server holds which FSMO role, this MSKB article explains how to transfer each of them).
- Give the servers some time to replicate directory information.
- Migrate other services (e.g. DHCP) as appropriate.
- Demote the old DC (
- Remove the old Server from the domain if it's to be decommissioned.
If old and new DC have the same operating system version, that's all you have to do. However, if the old DC runs Windows Server 2008 and the new DC will be running Server 2008 R2, you must extend the AD schema first. Copy the folder
\SUPPORT\ADPREP from the Windows Server 2008 R2 DVD to the old DC and run the following commands:
adprep /domainprep /gpprep
See this Technet article for details about the
adprep command. Run all 4 commands, even if you don't plan to run RODCs. After the commands completed successfully, you can proceed with step 2 from above.