Получить номер тома

function GetHardDiskSerial(const DriveLetter: Char): string;
var
  NotUsed:     DWORD;
  VolumeFlags: DWORD;
  VolumeInfo:  array[0..MAX_PATH] of Char;
  VolumeSerialNumber: DWORD;
begin
  GetVolumeInformation(PChar(DriveLetter + ':\'),
    nil, SizeOf(VolumeInfo), @VolumeSerialNumber, NotUsed,
    VolumeFlags, nil, 0);
    Result := Format('%s%8.8X',
    [VolumeInfo, VolumeSerialNumber])
end;



procedure TForm1.Button9Click(Sender: TObject);
begin
Edit1.Text:=GetHardDiskSerial('c');
end;