How to add a 2008R2 Domain Controller to a 2003 Domain

2008 domain controller

I have blogged about how to add a Microsoft Windows 2008R1 domain controller (DC) to a 2003 Domain. But, what if you need to add a Microsoft 2008R2 domain controller to a 2003 Domain? If you run adprep, you get an error because you cannot run a 64-bit executable in a 32-bit environment! The answer is to use adprep32 instead of adprep. Here are the entire instructions:

  1. Create the new 2008R2 machine, installing the operating system per normal
  2. In Windows Explorer, share the DVD drive out as read-only
  3. Run the command at the 2008 DOS prompt to see the fsmo owner: netdom query /domain ABC fsmo
    (Note: this command only works on 2008 Servers, not 2003 servers and is documented in its own blog post)
  4. Login to the 2003 DC that command (3) above tells you owns the fsmo roles
  5. Map a drive to the DVD in (2) that you shared by using Windows Explorer
  6. Copy the adprep directory off the DVD drive and locally onto the c:\ drive of the 2003 DC
    (Note: once you have copied the adprep directory you can unmap the drive and unshare the DVD)
    Then, you actually run the forest and domain upgrades:
  7. Goto a DOS prompt on the 2003 DC who owns the fsmo roles.
  8. ADPREP32 /Forestprep on the 2003 schema master
  9. ADPREP32 /rodcprep on the 2003 domain master
    (Note: only needed if installing read only domain controllers)
  10. ADPREP32 /domainprep on the 2003 infrastructure master

Finally, you can follow the steps to add the new 2008R2 server as a domain controller. Don’t know how? Watch for the next blog post.