var
  i : Integer;
  Device : string;
  hDevice : Cardinal;
  dummy : DWORD;
  bigBuf : DWord;
  r : DRIVE_LAYOUT_INFORMATION;

begin
  hDevice := CreateFile(PChar('\\.\PHYSICALDRIVE0'), GENERIC_WRITE or GENERIC_READ,
                        FILE_SHARE_READ or FILE_SHARE_WRITE,
                        nil, OPEN_EXISTING, 0, 0);

  if hDevice <> INVALID_HANDLE_VALUE then begin
    bigbuf:=sizeof(DRIVE_LAYOUT_INFORMATION) + 15 * sizeof(PARTITION_INFORMATION);
    if not DeviceIOControl(hDevice, IOCTL_DISK_GET_DRIVE_LAYOUT, nil, 0, @r,
                       bigbuf, dummy, nil) then begin
      showmessage(SysErrorMessage( GetLastError )+' '+inttostr(getlasterror));
    end
  end;
  CloseHandle(hDevice);
end;