The Client Network Utility lets you change the way ADO connects to SQL Server and MSDE by changing the protocols used. It also provides support for registering server instances as aliases. To run the Client Network Utility, select Run from the Start menu and type cliconfg.exe.
SQL Server and MSDE can listen on the Named Pipes protocol when installed under all Windows operating systems except Windows 98. If your SQL Server or MSDE is installed under Windows 98, you need to connect to it under TCP/IP instead.
If you need to connect to a server over the internet, or if your local network supports TCP/IP only, you need to use the TCP/IP protocol. Make sure that TCP/IP is enabled in the Client Network Utility and given top priority (moved to the top of the list or preferably used as the only protocol.) You can tell which protocol you are using from the error message you get when you attempt to connect. If the error message starts with [DBNETLIB], you are connecting under TCP/IP. If it starts with [DBNMPNTW], you are using Named Pipes.
In ADO 2.8, no protocols are enabled by default. This does not mean that you cannot connect. It simply means that a default sequence will be engaged in connecting to determine the protocol that will first succeed. Not all version of ADO default to the same protocols. ADO 2.5 for example, defaults to Named Pipes.