When you have experienced a domain controller failure either due to environmental hazards or equipment malfunction, you need to first repair the domain controller itself and then recover the data.
Because Active Directory is not only a transactional database, but a directory service on top of a transactional database, it is able to recover lost information because:
The database uses log files to recover lost information.
The directory service uses replication to recover data from other servers in the domain.
There are a variety of tools that can be used to repair the domain controller itself and recover Active Directory.
For more information about Windows 2000 disaster protection, including backups, restores, and repairs, see the Server Operations Guid e. Also see "System Recovery and Troubleshooting" in the product documentation, and Windows 2000 Server Help.