Recently we tried to migrate our old Windows Server 2003 box holding Active Directory FSMO roles to Windows 2008 R2. After joing 2008r2 to our domain we wanted to transfer all FSMO roles to it. It all went well without any problems.
Next step was to join another 2008r2 as second DC and demote old 2003. When you have TAPI3Directory partition in your AD you won’t be able to demote 2003 since it is last server that holds copy of it.
Windows 2008 and up doesnt have TAPI3Directory anyway so if you’re not using telephone services you are safe to delete it.
First login to the old 2003 and open command prompt, then type:
you will get something like:
SCP = TAPI3Directory.domain.local (Default) on domain controller 2003.dc.local
Next step is to delete the partition, type:
tapicfg remove /Directory:TAPI3Directory.domain.local /Server:2003.dc.local
After this TAPI3Directory will momentarily disappear from DNS structure of your AD you will be able to successfully demote old 2003 AD controller (if non other errors are found ;))