A simple Delphi routine that gets the serial number of a disk

function FindVolumeSerial(const Drive: PChar): string;

var

  VolumeSerialNumber: DWORD;

  MaximumComponentLength: DWORD;

  FileSystemFlags: DWORD;

  SerialNumber: string;

begin

  Result := '';

  GetVolumeInformation(Drive, nil, 0, @

    VolumeSerialNumber, MaximumComponentLength, FileSystemFlags, nil, 0);

  SerialNumber :=

    IntToHex(HiWord(VolumeSerialNumber), 4) + ' - ' +

    IntToHex(LoWord(VolumeSerialNumber), 4);

  Result := SerialNumber;

end;