I had followed the instructions here http://support.microsoft.com/kb/230306 to remove a child domain that wasn't needed and whose DC had crashed.
I removed the child domain called ae, and kept the other child domain called deva.
This was done about 1 week ago, when I Find in Active Directory Users and Computers I can see the ae domain listed at the top just above Entire Directory (whereas it used to be a sub folder under the main domain as a child domain) :
How can i remove this please?
This is always problematic. The correct thing to do, which in many cases is impossible, is to use dcpromo to remove the domain before taking the last DC for it offline, ensuring you specify that you are removing the last DC.
Failing that, Microsoft has a KB out about removing orphaned child domains. Basically, the process is to use ntdsutil to connect to NTDS on the operations master, select the child domain to remove, and use the remove selected domain command. Then, DS replication will occur eventually (if you have multiple DCs still, which you ought), and it should be gone.
When the domain persists even after this, you have to do a few things. First, go into the DNS manager on each DC and remove any entries related to the removed domain (SRV records and _msdcs subdomains in particular). Then, go into the domains and trusts MMC snapin and remove the trusts related to that domain. Also go to the sites and services snapin, and remove any DCs (replication nodes) that are dead and gone. In the users and computers snapin, also remove the computer and trust accounts related to the dead domain. Then, it should really be gone.
