Note: the problem has been resolved, the admin of the parent domain managed to remove the DC object. I gather he used ADSIEdit.
I'm working with an AD forest (in an isolated test environment, luckily, so failing all else we can blow everything away) and accidentally tried to create a subdomain using a cloned machine as the new domain controller.
Naturally enough, this didn't work. But the new subdomain got created, even though AD was not successfully installed on the putative DC, and now I can't get rid of it.
I started with this article. That didn't work because there was still metadata for the DC for the orphaned domain.
So I found this. Unfortunately this doesn't work either.
I opened AD Site and Services, opened the site in question, opened the Servers container, selected the DC in question, right-clicked on NTDS Settings and selected Delete. Clicked through "Are you sure", selected "This Domain Controller is permanently offline ...", confirmed that I wanted to do this even though the DC isn't in the domain I'm connected to, and confirmed that I wanted to do this even though this was the last DC in the domain.
Then it said "Windows cannot delete object LDAP://... because: A referral was returned from the server."
Anyone seen this before? Any ideas?