Event ID - 4321

Event Id4321
SourceNetBT
DescriptionThe name "WorkGroupName :1d" could not be registered on the Interface with IP address nnn.nnn.nnn.nnn. The machine with the IP address mmm.mmm.mmm.mmm did not allow the name to be claimed by this machine.
Event InformationWhen you start a Microsoft Windows XP workstation, you may receive the following error message:

Duplicate name exists.

Additionally, network basic input/output system (NetBIOS) name registration may not complete and the following event ID message may be logged in the System event log:

CAUSE:
This problem may be caused by a NetBIOS name conflict between the workstation and either another workstation with the same NetBIOS name, or a workgroup or domain with the same NetBIOS name as the workstation. 
RESOLUTION:
To resolve this problem, do one of the following:
Change the NetBIOS name of the workstation. For additional information, click the following article number to view the article in the Microsoft Knowledge Base: 
Delete the conflicting NetBIOS name in Windows Internet Naming Service (WINS). For more information about WINS, see the Windows 2000 Server Windows Internet Naming Service (WINS) Overview at the following Microsoft Web site :If your computer is connected to the network by cable, confirm that the cable is plugged in properly. If you have a wireless network connection, confirm that you have a signal and the proper credentials for the wireless network.

If the network connection is working properly, check the following possible causes and take corrective action:

The network is down. 
The firewall on your computer is blocking out network broadcast traffic. 
Your computers network interface card or driver is not functioning correctly.
Reference Links Frequently Asked Questions About Windows 2000 DNS and Windows Server 2003 DNS

HOW TO: Use the Netdom.exe Utility to Rename a Computer in Windows XP

More resolution information from MicroSoft.

Duplicate Name Exists" Error Message When You Start a Windows XP Workstation

Windows Server WINS Event Log Messages, Part 2: Event ID 4210 to 5300

When you start Windows XP Professional, you receive 'Duplicate name exists'

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