//WAVEファイルを再生するには
       System.Media.SoundPlayer player
           = new System.Media.SoundPlayer(
               @"C:\WINDOWS\Media\Windows Startup.wav");
       private void button1_Click(object sender, EventArgs e)
       {
           player.Play();
       }

       private void button2_Click(object sender, EventArgs e)
       {
           player.Stop();
       }