Err Msg: Cannot Create This File When This File Already Exists

The information in this article applies to:

• Microsoft Windows NT Server version 3.5
• Microsoft Windows NT Server version 3.51
• Microsoft Windows NT Server version 4.0

SYMPTOMS

When you attempt to establish trusts among a number of domains using User Manager for Domains, the following error message appears:

   Cannot create this file when this file already exists

CAUSE

This problem occurs when you attempt establish a trust with a domain that has the same domain security identification (SID) information as another domain that is already trusted, or has the same local Domain SID. This problem occurs when you:

• Rename a domain and the trust to the previous name is still in a trust relationship.
• Split a single domain into two domains by simply renaming the domain on some backup domain controller (BDC) and promoting it to a primary domain controller (PDC). In this case both domains have the same Domain SID.
• Create two domains through an automated process. For example, you install Windows NT once on a PDC and then performing a disk-to-disk copy to another identical computer, and then change the domain name.

WORKAROUND

To work around this problem:

• If a domain is renamed and previous trust relationships still exist, break all trusts established by the previous domain, and re-create the trusts for the new domain.

  -or-

• Reinstall all domain controllers in one of the domains (consider using a smaller domain). After you re-install the domain controllers, change the security on all objects which give permissions to objects in that domain.

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 3.5. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

A domain SID is generated during installation when you decide if you want the newly installed computer to be the PDC of a new domain. If there is no domain reachable on the network with that domain name, a new SID is generated. If you decide you want the computer to be a BDC, it browses the network for a PDC of a domain with that name and use that same domain SID. Once a SID is generated for a domain it does not change. This means that if you change a domain's name, it retains the same domain SID.