Creating a New DHCP Database

If the database has been corrupted and you do not have a workable backup copy, you have to delete the database, and then create a new one.

To create a new database

1. Move the file \systemroot\SYSTEM32\DHCP.MDB to another location.
2. Delete all files in the \systemroot\SYSTEM32\DHCP directory.
3. Delete all files in the \systemroot\SYSTEM32\DHCP\BACKUP\JET directory.
4. Copy the file SYSTEM.MDB from the Windows NT Server CD-ROM or floppy disks to the \systemroot\SYSTEM32\DHCP directory.
5. Restart the DHCP server.

When you check DHCP Manager, the scope still exists because the Registry holds the information on the address range of the scope, including a bitmap of the addresses in use. You need to reconcile the DHCP database to add database entries for the existing leases in the address bitmask. As clients renew, they are matched with these leases, and eventually the database is once again complete.

To reconcile the DHCP database

1. From the Scope menu, choose the Active Leases command.
2. In the Active Leases dialog box, choose the Reconcile button.

Although it is not required, you can force clients to renew their leases in order to update the DHCP database as quickly as possible. From the Command Prompt of the client computer, type the ipconfig/renew command.