low speed ADO.NET

private void SaveButton_Click(object sender, RoutedEventArgs e)
        {
           //update the DataBase with the TeacherName and Description Columns
            try
            {
                //create a connnection
                //OleDbConnection aConnection = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=c:\\users\\hosein\\db1.mdb");
                OleDbConnection aConnection = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=.\\db\\db1.mdb");
                aConnection.Open(); //open the connection
                //create an adapter using a sql command text and a connection that is open
                OleDbDataAdapter adapter = new OleDbDataAdapter("SELECT * FROM ComputerClasses", aConnection);
                #region check for compatibility between rows exist in the table and the rows we need
                adapter.SelectCommand = new OleDbCommand();
                adapter.SelectCommand.Connection = aConnection;
                adapter.SelectCommand.CommandText = "SELECT Count(ComputerClasses.RowNumber) AS CountOfRowNumber FROM ComputerClasses";
                byte a = Convert.ToByte(adapter.SelectCommand.ExecuteScalar()); // return the first row frist column element in the table that is returned
                //a contain the number of rows in the ComputerClass table
                adapter.InsertCommand = new OleDbCommand ();
                adapter.InsertCommand.Connection = aConnection;

                if (a < Settings.TotalClasses)
                {
                    adapter.SelectCommand.CommandText = "SELECT Max(ComputerClasses.RowNumber) AS MaxOfRowNumber FROM ComputerClasses";
                    byte b = Convert.ToByte(adapter.SelectCommand.ExecuteScalar()); // now b contain the maximum number in the RowNumber column in the table
                    // we use it to have the ascend form in the RowNumber column and it is essential because we use the order in the update phase
                    for (byte l = 0; l < (Settings.TotalClasses - a); l++)
                    {
                        adapter.InsertCommand.CommandText = string.Format("INSERT INTO ComputerClasses (RowNumber, TeacherName, Description )VALUES ({0},\"Teacher Name\", \"Description\")", ++b);
                        adapter.InsertCommand.ExecuteNonQuery();
                    }
                }
                #endregion
                // creating an update command
                adapter.UpdateCommand = new OleDbCommand();
                //allocating the connection to the comamand
                adapter.UpdateCommand.Connection = aConnection;
                for (byte i = 0; i < Settings.TotalClasses; i++) //iterating to each row and update each row with the database rows
                {
                    // creating the command text (SQL SYNTAX)
                    adapter.UpdateCommand.CommandText = "UPDATE ComputerClasses SET TeacherName = '" + RowArray[i].teacherName.Text.ToString() +
                        "', Description = '" + RowArray[i].description.Text.ToString() + "' WHERE RowNumber = " + (i + 1).ToString();
                    // tell to database to execute the command that is generated in the previous line
                    adapter.UpdateCommand.ExecuteNonQuery();
                }
                aConnection.Close(); //close the connection
                MessageBox.Show("Successfully Updated"); // show a message say to user that the operation is done successfully
            }
            catch
            {
                MessageBox.Show("Error Code 1, Connecting to DataBase"); //if any error occur during the operation to database
                // the try block prevent the system crash and just a message windows apear and say to user what happend with an
                // error code
            }
        }