Error or connection problems when you configure WINS addresses for a WINS server

This article provides a solution to problems that occur when you configure the Windows Internet Naming Service (WINS) addresses for a WINS server.


WINS is deprecated. Therefore, you should no longer use it as a name resolution system.

Original KB number:   150737


When you configure the Primary and Secondary WINS address for a WINS server, you receive the following error message:

The WINS server is already in the list.

Alternatively, clients begin to experience connection problems even if you don't see this error message and the WINS server appears to function correctly. The problems disappear in time but recur when the affected WINS server restarts.


These problems indicate that the WINS server's Primary and Secondary WINS addresses aren't correctly configured. You can't use the same address for both the Primary and Secondary WINS address.

If you set the Primary WINS address to the address of a different WINS server and set the Secondary WINS address to the WINS server's own address, you won't receive the error message. However, when the WINS server registers its services, it might register some of those services on the different WINS server. After some time, the server registers the services correctly in its local WINS database. This causes some records to be registered on both WINS servers. This situation is known as "split registration."

Split registration can cause connection problems. Clients might not be able to connect to the affected WINS server or its services. As the split registration replicates to other WINS servers, the likelihood of connection problems for clients increases. The exact conditions that cause failure vary. The severity of the problem depends on your replication scheme.

Split registration is a temporary condition. After the newly started WINS server stops registering its services remotely, the remote WINS server stops renewing the incorrect registrations. Eventually, the corrected registrations replicate throughout the system and resolve the connection problems. Hopwever, until you correct the address configuration of the affected WINS server, the problem recurs when that WINS server restarts.


We recommend that you set a WINS server to always point to itself as the Primary WINS address and not as the Secondary WINS address. This configuration avoids split registrations and other problems.


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

More information

When a Windows Server-based computer runs the WINS service and participates in WINS database replication on the network, you must carefully configure the destination that the WINS server uses to resolve its own name.

You can configure this setting in the Network control panel, in TCP/IP Protocol > Configuration. You can also configure this setting by using the registry (although if the address is already added, you don't have to add it again).

Potential WINS registration conflicts

When any WINS-enabled computer starts, it registers different kinds of services with WINS. Typically, the computer has a Primary and Secondary WINS address configured in the TCP/IP setup. If the Primary WINS address doesn't respond to the registration attempts, the computer tries the Secondary WINS address.

When a WINS server starts, it should register its own services in its own local WINS database before it connects to other WINS servers. However, the WINS server might try to register services before its own WINS service starts. If the Primary WINS address is set to a remote WINS server, or if both the WINS addresses are set to remote WINS servers, the newly started WINS server might register its own services with a remote WINS server. After the local WINS service starts, the WINS server registers its services locally. However, this doesn't immediately remove the remote registrations.


Consider a WINS server (SRV1) that is a domain controller that runs in the domain. SRV1 points to itself as the Primary WINS server and points to another WINS server (WINS2) as the Secondary WINS server. When SRV1 starts, it tries to register its services before its own WINS service starts. Because those registrations fail, SRV1 tries to register them at WINS2. If WINS2 is available, it accepts the registration requests. During this process, SRV1 continues to check its local WINS service. When SRV1 detects that its WINS service is running, it stops sending registration requests to WINS2 and handles them locally instead.

After the WINS records replicate between SRV1 and WINS2, the databases on both servers show the following record of ownership:

Records that SRV1 owns Records that WINS2 owns
SRV1<20> Other registrations from SRV1

Because of the split registration, clients might not be able to connect to SRV1 or might not resolve the domain. Eventually, SRV1 correctly registers all its service records locally, and WINS2 determines that it no longer owns the SRV1 registrations. The corrected registrations from both SRV1 and WINS2 then replicate to the remaining WINS servers. This process removes the risk of experiencing connection problems.