A. No. Server 2008 has an Active Directory (AD) service that you can restore, it's only usable for certain scenarios. If you need to restore an AD database, you need to boot the DC into Directory Services Restore Mode (DSRM), restore the backup, mark the objects you want to keep as authoritative, and boot back into normal mode.

The AD service's ability to restart can be used is if you have a DC that still has an object that has been changed or deleted (perhaps you have a lag configured for the DC's site). You could stop NTDS, mark objects as authoritative, then restart NTDS. No reboot is required.

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