Получить серийный номер диска

procedure ShowDriveSerialNo(Drive : String); // Drive as 'c:' or 'd:', ...
var VolSerNum: DWORD;
    Dummy1, Dummy2: DWORD; 
begin 
  if GetVolumeInformation(drive+'\', NIL, 0, @VolSerNum, Dummy1, Dummy2, NIL, 0) then 
    ShowMessage(Format('%.4x:%.4x', [HiWord(VolSerNum), LoWord(VolSerNum)]));
end;

// --------------------- //

function GetDriveSerialNo(Drive : String) : String; // Drive as 'x:' ...
var VolSerNum: DWORD;
    Dummy1, Dummy2: DWORD; 
begin 
  if GetVolumeInformation(drive+'\', NIL, 0, @VolSerNum, Dummy1, Dummy2, NIL, 0) then 
    Result := Format('%.4x:%.4x', [HiWord(VolSerNum), LoWord(VolSerNum)]);
end;