Your Windows 2000 DNS server posts the following every 5 minutes:

Event ID: 4000
Source: DNS
Type: Error
Category: None
User: N/A
Computer: <ComputerName>
Description: The DNS server was unable to open Active Directory. This DNS server is configured to obtain and use information from the directory for this zone and is unable to load the zone without it. Check that the Active Directory is functioning properly and reload the zone.

The behavior will occur if the DNS server IP address is incorrect.

To resolve this problem:

01. Open the DNS application from Administrative Tools.

02. Right-click the DNS server that is exhibiting this behavior and press Properties.

03. Select the Interfaces tab.

04. Select Only the following IP addresses.

05. Type the first IP address of the correct network adapter into the IP address box and press Add.

06. Press OK.

07. Close the DNS tool.

08. Use Control Panel to double-click Network and Dial-up Connections.

09. Right-click the Local Area Connection for the IP address that you specified in step 05, and press Properties.

10. Select Internet Protocol (TCP/IP) and press Properties.

11. Type the IP address that you used in step 05 into the Preferred DNS server and press OK.

12. Press OK.

13. Close Network and Dial-up Connections.