Windows server 2012R2 as additional domain controller along with Server 2008R2 fails


On running ADPrep passes all prerequisite, but fails in the last stage with the below error:

ADPrep execution failed --> System.ComponentModel.Win32Exception (0x80004005): A device attached to the system is not functioning.

ADPrep log says:

Adprep requires access to existing forest-wide information from the schema master in order to complete this operation.

I'm using the credentials of Enterprise Admin (schema admin too) couldn't find why it still throws access denied error.

asked on Server Fault Apr 1, 2014 by Nandan • edited Apr 1, 2014 by EEAA

3 Answers


I'd comment on the original question so I can gather more info before posting my answer, but I don't have enough reputation yet as I'm new; go figure right :)

Anyway, I've ran into this twice for two different clients, one that was running SBS 2003 and another running 2008 R2 like you are. Both times had a few different tweaks but ultimately the solution turned out to be this:

  1. Remove the Active Directory Domain Services role from the 2012R2 server if you have already installed it.

  2. Reboot.

  3. I know you already said you had Enterprise and Schema rights, but make sure you're using an account with Enterprise, Schema, and Domain admin creds.

  4. Reboot the 2008 R2 DCs; yes all of them.

  5. Go to the 2012 R2 server and add the Active Directory Domain Services role and reboot after it successfully adds.

  6. Once logged back into the 2012 R2 server open Server Manager and on your post installation tasks you should see something similar to this screenshot: enter image description here

picture source:

click on the link "Promote this server to a domain controller" (ADPrep (both forest and domain) will run automatically without manually needing to have you run it from a command prompt)

  1. Reboot the server once the dcpromo finishes.

If you are still having trouble please look for the value in ADSI Edit for your server entitled "ClaimIsValueSpaceRestricted"; it will either be true or false. Let me know if it's true or false and if it's greyed out or not. We can troubleshoot further should we need to, but steps 1-7 should resolve your issue.

answered on Server Fault Apr 20, 2014 by Brad Bouchard

Here is what I did to get it to work

  • Setup a Windows server 2008
  • Promoted it to a domain controller.
  • I still got the ADPrep execution failed --> System.ComponentModel.Win32Exception (0x80004005): A device attached to the system is not functioning.
  • Some discussion I saw suggested access to the schema master was the issue and recommended moving the schema master to the 2008 server.
  • This wouldn’t work from the Schema Master MMC so I used ntdsutil.
  • Went back to my 2012 server and attempted to promote it again. When given a choice out what DC to replicate from, I pointed to the 2008 server. I got a lot further that time, but still failed. Ran it again and pointed it to the old SBS 2003 server and it worked.
answered on Server Fault Feb 22, 2015 by Porter Jervis • edited Feb 22, 2015 by masegaloeh

I had the exact same error and the solution from solved it for me:

Check the Remote Registry service on the 2003 domain controller is configured as follows:

Startup type: Automatic

Service Status: Started

Security context: NT Authority\LocalService (In Log On tab of remote registry service)

Then promote the 2012 server again.

answered on Server Fault Jun 23, 2016 by Silvan Wehrli • edited Jun 11, 2020 by Community

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