This Active Directory domain controller currently performs the RID operations master role. If you remove Active Directory ...

This Active Directory domain controller currently performs the RID operations master role. If you remove Active Directory Domain Services (AD DS) from this computer, you might have problems creating new user accounts, computer accounts, and security groups. Before you continue, transfer the RID master role to a domain controller in the same domain as this domain controller. If it is not possible to transfer the role, first remove AD DS from this computer, and then use Ntdsutil.exe to seize the role. Use Ntdsutil on the domain controller that you plan to seize the role to; if possible, use a recent replication partner in the same site as this domain controller.  For more information about transferring and seizing operations master roles, see article 255504 in the Microsoft Knowledge Base (http://go.microsoft.com/fwlink/?LinkId=80395).