Connection String for Lan Connceted server .... Try this

Data Source=myServerAddress;Initial Catalog=myDataBase;User Id=myUsername;Password=myPassword;

Use serverName\instanceName as Data Source to connect to a specific SQL Server instance.

Are you using SQL Server 2005 Express? Don't miss the server name syntax Servername\SQLEXPRESS where you substitute Servername with the name of the computer where the SQL Server 2005 Express installation resides. =========================================================================== or May be try this Link http://connectionstrings.com/Forum/mysql/connecting-to-mysql-from-another-pc-on-the-network