[DarkByte]

He encontrado esto en clubdelphi: Cómo sacar el número de serie de un cd de audio, truco 424:

procedure TForm1.Button1Click(Sender: TObject);
 
  function AudioCDNum(Unidad: char):string;
  var 
    mp            : TMediaPlayer;
    MInfo         : TMCI_INFO_PARMS;
    SerialN       : array[0..255] of char;
 
  begin 
    Result:='';
    mp := TMediaPlayer.Create(nil);
 
    try
      with mp do 
      begin 
        Visible    := false;
        Parent     := Application.MainForm;
        Shareable  := true;
        DeviceType := dtCDAudio;
        FileName   := Unidad+':';
        Open;
      end; 
      Application.ProcessMessages;
 
      FillChar(SerialN, sizeof(SerialN), #0);
      FillChar(MInfo, sizeof(MInfo), #0);
      MInfo.lpstrReturn := @SerialN;
      MInfo.dwRetSize := 255;
      if mciSendCommand(Mp.DeviceId,
                        MCI_INFO,
                        MCI_INFO_MEDIA_IDENTITY,
                        longint(@MInfo)) <> 0
        then Raise Exception.Create('Error');
      mp.Close;
 
      Result:=String(SerialN);
    finally
      Application.ProcessMessages;
      mp.free;
    end; 
  end; 
 
begin 
  Label1.Caption:=AudioCDNum('F');
end;

Espero que te sirva de ayuda...