I recently removed a domain controller for a windows 2000 child domain, by using windows dcpromo option. When asked if this domain controller is the last controller in the domain (which it was), I answered yes as I wanted the domain removing entirely.
Although the domain is no longer listed in Active Directory Domains and Trusts, it is still showing in one or two places:
When logging onto the network, the domain still appears in the drop-down domain list on the log on screen.
In the administrator Wins tool, it shows if I try to add a new replication partner. It is listed on the browse list, but is not shown as a child domain, i.e indented to the right, it is shown not indented as per the main domain.
I've looked through dns on the domain controllers in the main domain and the domain controllers in the remaining two domains and can find know reference to the deleted domain.