One way of connecting a windows application to a SQL Server is to use ODBC drivers. The requirements to do this is summarized here:

* The SQL Server must have TCP/IP protocol enabled with a specific port number.

* The SQL Server Browser Service must be running on the server machine.

* A ODBC DSN must be created to represent the connection to SQL Server on the specified port number.

* The local windows application must be able to support ODBC API calls.

The diagram below shows how MS Access can connect to a SQL Server through the ODBC driver:

SQL Server ODBC Connection