Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk. Note that you should back up the registry before you edit it. This article assumes that the source domain is running Windows NT 4.0 Service Pack 4 or later, and that the target domain is a Windows 2000-based domain in Native mode.
Trusts Configure the source domain to trust the target domain.
Configure the target domain to trust the source domain. Groups Add the Domain Administrators global group from the source domain to the Administrators local group in the target domain. Add the Domain Administrators global group from the target domain to the Administrators local group in the source domain. Auditing Enable auditing for the success and failure of user and group management on the source domain. Enable auditing for the success and failure of Audit account management on the target domain in the Default Domain Controllers policy.