function GetHardDiskSerial(const DriveLetter: Char): string;
var
  NotUsed:     DWORD;
  VolumeFlags: DWORD;
  VolumeInfo:  array of Char;
  VolumeSerialNumber: DWORD;
begin
  GetVolumeInformation(PChar(DriveLetter + ':'),
    nil, SizeOf(VolumeInfo), @VolumeSerialNumber, NotUsed,
    VolumeFlags, nil, 0);
  Result := Format('Label = %s   VolSer = %8.8X',
    [VolumeInfo, VolumeSerialNumber])
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
  ShowMessage(GetHardDiskSerial('c'));
end;

@DelphiExpert: Yub betul bro Taruna bilang (eh bro elu ni tentara apa mobil daihatsu sih) hihihi...

unit IdeSN;
interface
//-------------------------------------------------------------
// Tries to extract the serial number from the first IDE disk that is found in the system.
// Returns an empty string if IDE disk is not found.
  function GetIdeSN : String;
//-------------------------------------------------------------
// Tries to extract the serial number from specified IDE disk.
//
// Parameters:
//   ControllerNumber - SCSI port number of the controller.
//   DriveNumber - Device index (0..4).
//
// Raises OSError exception in case of any error during this operation.
//
// Notes:
//  1. The parameter ControllerNumber is ignored on Windows 9x/ME platforms and should be 0.
//  2. This function CAN NOT extract SCSI disk serial number.
//
  function GetIdeDiskSerialNumber( ControllerNumber, DriveNumber : Integer ) : String;
//=============================================================
implementation
uses
  Windows,
  SysUtils; // only for Win32Platform, SysErrorMessage and class Exception
{$IFDEF VER150}
{$DEFINE VER140}
{$ENDIF}
{$IFNDEF VER140}
procedure RaiseLastOSError;
begin
  RaiseLastWin32Error;
end;
{$ENDIF}
//-------------------------------------------------------------
// Tries to extract the serial number from specified IDE disk.
//
// Parameters:
//   ControllerNumber - SCSI port number of the controller.
//   DriveNumber - SCSI port number of the controller.
// Notes:
//  1. The parameter ControllerNumber is ignored on Windows 9x/ME platforms and should be 0.
//  2. This function CAN NOT extract SCSI disk serial number.
//
function GetIdeDiskSerialNumber( ControllerNumber, DriveNumber : Integer ) : String;
type
  TSrbIoControl = packed record
    HeaderLength : ULONG;
    Signature    : Array of Char;
    Timeout      : ULONG;
    ControlCode  : ULONG;
    ReturnCode   : ULONG;
    Length       : ULONG;
  end;
  SRB_IO_CONTROL = TSrbIoControl;
  PSrbIoControl = ^TSrbIoControl;
  TIDERegs = packed record
    bFeaturesReg     : Byte; // Used for specifying SMART "commands".
    bSectorCountReg  : Byte; // IDE sector count register
    bSectorNumberReg : Byte; // IDE sector number register
    bCylLowReg       : Byte; // IDE low order cylinder value
    bCylHighReg      : Byte; // IDE high order cylinder value
    bDriveHeadReg    : Byte; // IDE drive/head register
    bCommandReg      : Byte; // Actual IDE command.
    bReserved        : Byte; // reserved for future use.  Must be zero.
  end;
  IDEREGS   = TIDERegs;
  PIDERegs  = ^TIDERegs;
  TSendCmdInParams = packed record
    cBufferSize  : DWORD;                // Buffer size in bytes
    irDriveRegs  : TIDERegs;             // Structure with drive register values.
    bDriveNumber : Byte;                 // Physical drive number to send command to (0,1,2,3).
    bReserved    : Array of Byte;  // Reserved for future expansion.
    dwReserved   : Array of DWORD; // For future use.
    bBuffer      : Array of Byte;  // Input buffer.
  end;
  SENDCMDINPARAMS   = TSendCmdInParams;
  PSendCmdInParams  = ^TSendCmdInParams;
  TIdSector = packed record
    wGenConfig                 : Word;
    wNumCyls                   : Word;
    wReserved                  : Word;
    wNumHeads                  : Word;
    wBytesPerTrack             : Word;
    wBytesPerSector            : Word;
    wSectorsPerTrack           : Word;
    wVendorUnique              : Array of Word;
    sSerialNumber              : Array of Char;
    wBufferType                : Word;
    wBufferSize                : Word;
    wECCSize                   : Word;
    sFirmwareRev               : Array of Char;
    sModelNumber               : Array of Char;
    wMoreVendorUnique          : Word;
    wDoubleWordIO              : Word;
    wCapabilities              : Word;
    wReserved1                 : Word;
    wPIOTiming                 : Word;
    wDMATiming                 : Word;
    wBS                        : Word;
    wNumCurrentCyls            : Word;
    wNumCurrentHeads           : Word;
    wNumCurrentSectorsPerTrack : Word;
    ulCurrentSectorCapacity    : ULONG;
    wMultSectorStuff           : Word;
    ulTotalAddressableSectors  : ULONG;
    wSingleWordDMA             : Word;
    wMultiWordDMA              : Word;
    bReserved                  : Array of Byte;
  end;
  PIdSector = ^TIdSector;
const
  IDE_ID_FUNCTION = $EC;
  IDENTIFY_BUFFER_SIZE       = 512;
  DFP_RECEIVE_DRIVE_DATA        = $0007c088;
  IOCTL_SCSI_MINIPORT           = $0004d008;
  IOCTL_SCSI_MINIPORT_IDENTIFY  = $001b0501;
  DataSize = sizeof(TSendCmdInParams)-1+IDENTIFY_BUFFER_SIZE;
  BufferSize = SizeOf(SRB_IO_CONTROL)+DataSize;
  W9xBufferSize = IDENTIFY_BUFFER_SIZE+16;
var
  hDevice : THandle;
  cbBytesReturned : DWORD;
  s : String;
  pInData : PSendCmdInParams;
  pOutData : Pointer; // PSendCmdInParams;
  Buffer : Array of Byte;
  srbControl : TSrbIoControl absolute Buffer;
  procedure ChangeByteOrder( var Data; Size : Integer );
  var ptr : PChar;
      i : Integer;
      c : Char;
  begin
    ptr := @Data;
    for i := 0 to (Size shr 1)-1 do
    begin
      c := ptr^;
      ptr^ := (ptr+1)^;
      (ptr+1)^ := c;
      Inc(ptr,2);
    end;
  end;
begin
  Result := '';
  FillChar(Buffer,BufferSize,#0);
  if Win32Platform=VER_PLATFORM_WIN32_NT then
    begin // Windows NT, Windows 2000
      Str(ControllerNumber,s);
      // Get SCSI port handle
      hDevice := CreateFile(
        PChar('\\.\Scsi'+s+':'),
        GENERIC_READ or GENERIC_WRITE,
        FILE_SHARE_READ or FILE_SHARE_WRITE, nil, OPEN_EXISTING, 0, 0 );
      if hDevice=INVALID_HANDLE_VALUE then RaiseLastOSError;
      try
        srbControl.HeaderLength := SizeOf(SRB_IO_CONTROL);
        System.Move('SCSIDISK',srbControl.Signature,8);
        srbControl.Timeout      := 2;
        srbControl.Length       := DataSize;
        srbControl.ControlCode  := IOCTL_SCSI_MINIPORT_IDENTIFY;
        pInData := PSendCmdInParams(PChar(@Buffer)+SizeOf(SRB_IO_CONTROL));
        pOutData := pInData;
        with pInData^ do
        begin
          cBufferSize  := IDENTIFY_BUFFER_SIZE;
          bDriveNumber := DriveNumber;
          with irDriveRegs do
          begin
            bFeaturesReg     := 0;
            bSectorCountReg  := 1;
            bSectorNumberReg := 1;
            bCylLowReg       := 0;
            bCylHighReg      := 0;
            bDriveHeadReg    := $A0 or ((DriveNumber and 1) shl 4);
            bCommandReg      := IDE_ID_FUNCTION;
          end;
        end;
        if not DeviceIoControl( hDevice, IOCTL_SCSI_MINIPORT, @Buffer, 
          BufferSize, @Buffer, BufferSize, cbBytesReturned, nil ) then RaiseLastOSError;
      finally
        CloseHandle(hDevice);
      end;
    end
  else
    begin // Windows 95 OSR2, Windows 98
      hDevice := CreateFile( '\\.\SMARTVSD', 0, 0, nil, CREATE_NEW, 0, 0 );
      if hDevice=INVALID_HANDLE_VALUE then RaiseLastOSError;
      try
        pInData := PSendCmdInParams(@Buffer);
        pOutData := PChar(@pInData^.bBuffer);
        with pInData^ do
        begin
          cBufferSize  := IDENTIFY_BUFFER_SIZE;
          bDriveNumber := DriveNumber;
          with irDriveRegs do
          begin
            bFeaturesReg     := 0;
            bSectorCountReg  := 1;
            bSectorNumberReg := 1;
            bCylLowReg       := 0;
            bCylHighReg      := 0;
            bDriveHeadReg    := $A0 or ((DriveNumber and 1) shl 4);
            bCommandReg      := IDE_ID_FUNCTION;
          end;
        end;
        if not DeviceIoControl( hDevice, DFP_RECEIVE_DRIVE_DATA, pInData, 
          SizeOf(TSendCmdInParams)-1, pOutData, W9xBufferSize, cbBytesReturned, nil ) then 
          RaiseLastOSError;
      finally
        CloseHandle(hDevice);
      end;
    end;
  with PIdSector(PChar(pOutData)+16)^ do
  begin
    ChangeByteOrder(sSerialNumber,SizeOf(sSerialNumber));
    SetString(Result,sSerialNumber,SizeOf(sSerialNumber));
  end;
  Result := Trim(Result);
end;
//-------------------------------------------------------------
function GetIdeSN : String;
var
  iController, iDrive, maxController : Integer;
begin
  Result := '';
  maxController := 15;
  if Win32Platform<>VER_PLATFORM_WIN32_NT then maxController := 0;
  for iController := 0 to maxController do
  begin
    for iDrive := 0 to 4 do
    begin
      try
        Result := GetIdeDiskSerialNumber(iController,iDrive);
        if Result<>'' then Exit;
      except
        // ignore exceptions
      end;
    end;
  end;
end;
end.