Restoring the DHCP Database from Backup

In the case of a server crash and recovery, you might need to restore and then reconcile the DHCP database. To force DHCP to restore the database from backup, follow these steps:

1. If necessary, restore a good copy of the %SystemRoot%\System32\DHCP\Backup directory from the archive. Afterward, start the DHCP console, right-click the server you want to restore, and then click Restore.
2. In the Browse for Folder dialog box, select the folder that contains the backup you want to restore, and then click OK.
3. During restoration of the database, the DHCP Server service is stopped. As a result, DHCP clients are temporarily unable to contact the DHCP server to obtain IP addresses.

Cr. https://technet.microsoft.com/