c# Wiso bekommen ich keine verbindung

OleDbConnection con = new OleDbConnection(); 
            con.ConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:\data.mdb"; 


            string strSQL = "SELECT name FROM groups";


            con.Open();


            OleDbCommand cmd = new OleDbCommand(strSQL, con);
            OleDbDataReader dr = cmd.ExecuteReader();


            while(dr.Read())
            {
                MessageBox.Show("ok");
            }