Backing up Active Directory should always be a very crucial part of your backup regime. If Active Directory gets corrupted for whatever reason (a virus written to do this very thing for example) then without a backup you are in trouble. Here I describe exactly how to backup Active Directory.

The easiest way to backup active directory is to use the built in NTBackup utility.

1.) Logon to a domain controller you wish to backup.
2.) Go to start, all programs, accessories, system tools, backup (or type ntbackup in the run box)
3.) Click on the backup tab
4.) Select System State.
5.) Now select a location to save the file.
6.) Make sure this file is itself backed up as part of your normal backup regimes.

This backup can only be restored onto the same domain controller. For this reason I would always backup all of the domain controllers.

How to restore Active Directory on 2003 Server