A Duplicate Name Exists On the Network

What you can do to resolve duplicate network name issues with Windows devices

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After starting up a Microsoft Windows computer connected to a local network, you may see one of the following error messages:

"A duplicate name exists on the network"

"Duplicate name exists"

"You were not connected because a duplicate name exists on the network" (system error 52)

These errors will all prevent a Windows computer from joining the network. The device will start up and function in an offline (disconnected) mode only.

 

Why Duplicate Name Issues Occur on Windows

These errors are found only on networks which have old Windows XP PCs or are using Windows Server 2003. Windows clients display "A duplicate name exists on the network" when they detect two devices with the same network name. This error can be triggered in several ways:

  • (most commonly) two Windows computers were given the same name Computer Name under Windows System Properties
  • the local network has been set up to use a Windows Workgroup, and the name chosen for the workgroup is the same as the name of some other device on the network (such as a home broadband routers
  • (least commonly) a Windows server on the network has been configured with two different network names

Note that the computer on which these errors are reported is not necessarily one of the devices having a duplicate name. Microsoft Windows XP and Windows Server 2003 operating systems use NetBIOS and the Windows Internet Naming Service (WINS) system to maintain a shared database of all the network names.

In the worst case, any and every NetBIOS device on the network might report these same errors. (Think of it as a neighborhood watch where devices are noticing a problem down the street. Unfortunately, the Windows error messages do not say exactly which neighbor devices are having the name dispute.)

Resolving Duplicate Name Exists Errors

To resolve these errors on a Windows network, follow these steps:

  1. If the network is using a Windows workgroup, ensure the name of the workgroup is different than the name (SSID) of any routers or wireless access points
  2. Determine which two Windows devices have the same name. Check each computer name in Control Panel.
  3. In Control Panel, change the name of one of the offending computers to one that is not used by other local computers and also different from the Windows workgroup name, then reboot the device
  4. On any device where the error message persists, update the computer's WINS database to remove any lingering reference to the old name.
  5. If receiving system error 52 (see above), update the configuration of the Windows server so that it has only one network name.
  6. Strongly consider upgrading any old Windows XP devices to a newer version of Windows.

More - Naming Computers on Windows Networks