Named Pipes support cannot be removed on a virtual server that is running SQL Server 2000 SP3

After you install Microsoft SQL Server 2000 Service Pack 3 (SP3) on a SQL Server 2000 virtual server, the database administrator or the SQL Server administrator cannot remove Named Pipes support. If Named Pipes support was previously removed, the server continues to listen only on TCP.

Note The default network libraries that are installed on a virtual server are TCP and Named Pipes.

If Named Pipes support has been removed and the virtual server fails does not come online with the remaining network library, the server refuses all incoming connections. The following problems occur:

• The administrator cannot correct the problem by using Server Network Utility. Server Network Utility requires that the client establish a connection to the server before making any changes to the registry.
• Changes to the registry cannot be made manually because of the behavior of the Windows Checkpoint system. If you try to make manual changes to the registry, the checkpoint file reverts the values to the original values.

Although Named Pipes support is not required for a virtual server, Microsoft recommends that both network libraries must be present on the system because of the following reasons:

• Having both network libraries available permits an administrator or an alternative interprocess communication (IPC) mechanism to repair the system.
• Clients can continue to work with the virtual server, even if only one server-side network library is available.

Note On a virtual server that is running SQL 2000 SP3a, an administrator can disable Named Pipes support through SQL Server Enterprise Manager in SQL Server 2000 SP2 or earlier.

If the named pipe on the server is not valid, SQL Server shuts down all "listen on" threads during SQL Server startup and does not permit any users to connect.