We have a PDC server running NT4.0 sp6a and a BDC server running NT4.0 sp6a. Workstations are W2K, NT4.0 and 98 mix. Heres the problem. The PDC went down. Software failure. The BDC was promoted to a PDC to run the show while the orginal PDC was rebuilt. Once the origianl PDC was back up and running the BDC ” currently acting as a PDC ” was demoted back to a BDC and the PDC was brought back on line. Once everything was up and running both the BDC and the PDC lost all user info, and computer info in user mgr and server mgr. Once we realized we couldnt reterive the lost info we re added all workstations and user account. Now that all accounts have been added back we now receive errors from the BDC. These errors are reported everytime a user or PC logs onto the network. The error reads as follows ” The computer * tried to connect to the server “BDC that was promoted then demoted” using the trust relationship established by the DOMAIN. However the computer lost the correct SID when the domain was reconfigured. Reestablish the trust. Why do I still get this error? The original PDC is back and the BDC is back to a BDC. What gives?