When you install Microsoft® SQL Server™, SQL Server Setup makes an entry in the Microsoft Windows® 2000 registry that enables Named Pipes clients to see SQL Server in a server enumeration box in SQL Query Analyzer. SQL Server automatically announces itself as a service over Named Pipes to make it easier to locate servers running an instance of SQL Server. However, if you are using Active Directory™, the directory service included in Windows 2000, this functionality is no longer necessary.
Stop SQL Server from announcing itself over Named Pipes by running the NET CONFIG SERVER command with the switch as /HIDDEN:YES. You can reveal the server at any time.
To reveal or cancel the announcement of SQL Server on a network