When you try to promote a Windows NT 4.0 BDC to a PDC, you receive the following System events:

Event ID 3096 - The Windows NT domain controller for this domain could not be located.

Event ID 5516 - The computer or domain <computername> trusts domain <domainname>. This may be an indirect trust. However, <computername> and <domainname> have the same security identifier. NT should be reinstalled on <domainname> or <computername>.

You might have a trust relationship from the BDC to the domain of the BDC.

To fix the problem, you must delete this trust:

1. In User Manager for Domains, Press Policies / Trust Relationships.

2. Remove Trust Relationships for the domain.

3. Start Server Manager. The domain should be available and manageable.

4. Select the BDC to be promoted.

5. Press Computer / Promote to Primary Domain Controller.