When you use the data wizards in .NET 2.0, the connection string property is read only. However, the following code shows you how to change the connection string:

        'set a reference to system.configuration        'set the following imports stratement above your class         'Imports System.Configuration        ' Get the application configuration file.        Dim config _        As System.Configuration.Configuration = _        ConfigurationManager.OpenExeConfiguration( _        ConfigurationUserLevel.None)        'the full connection string name.   normally designer generated is assemblyname         '.My.MySettings.connectionName         'below is a sample how i used it with my test app         Dim csName As String = "TestRptWO.My.MySettings.DbCon"               ' Create a connection string element         '(use the connection string of your choice; I tested it with SQL Server,         but it should work for any provider )        Dim csSettings _        As New ConnectionStringSettings( _        csName, _        "LocalSqlServer: data source=127.0.0.1;Integrated Security=SSPI;" + _        "Initial Catalog=aspnetdb", "System.Data.SqlClient")        ' Get the connection strings section.        Dim csSection _        As ConnectionStringsSection = _        config.ConnectionStrings        'first remove the old section from the collection          csSection.ConnectionStrings.Remove(csName)        ' Add the new element.        csSection.ConnectionStrings.Add(csSettings)        ' Save the configuration file.        config.Save(ConfigurationSaveMode.Modified)