Why Duplicate Name Problems Occur on Windows
Windows clients display “A duplicate name exists on the network” when two devices are detected with the same network name. This error can be triggered in several ways:
Two Windows computers use the same generic name. The local network is set up to use a Windows Workgroup, and the name chosen for the workgroup is the same as the name of another device on the network, such as a home broadband router. A Windows server on the network is configured with two different network names.
The computer on which these errors are reported is not necessarily one of the devices with a duplicate name. Microsoft Windows XP and Windows Server 2003 operating systems use NetBIOS and the Windows Internet Naming Service system to maintain a shared database of network names. Any or every NetBIOS device on the network might report these same errors. Think of it as a neighborhood watch where devices notice a problem down the street. The Windows error messages do not say exactly which neighbor devices experience the name dispute.
How to Resolve Duplicate Name Exists Errors
To resolve these errors on a Windows network: