When ADO communicates with a database it does so through a networking library. Your selection of a networking library will be determined by the data provider and system configuration, and can have a significant impact on database access speed. For example, if you are accessing data from a Microsoft SQL Server database your access speed, in general, will be faster if you use the TCP/IP networking library. However, if SQL Server is running on the same computer as IIS, you may find some performance improvements by using the Named Pipes networking library.
You can set the networking library for a DSN by using the Data Sources (ODBC) option in Control Panel. Once you set a library for one connection, it will become the default library for all subsequent connections, as well as for any DSN-less connections that your application may use.
Note If you change the network library from Named Pipes to TCP/IP, be sure not to remove Named Pipes as one of the options, because SQL Server Enterprise Manager relies on this library.