//procedure TMainForm.CD_Lock(Locked: Boolean, DriveLetter: string);

const
  IOCTL_STORAGE_MEDIA_REMOVAL = $002D4804;
var
  hDrive: THandle;
  Returned: DWORD;
  DisableEject: boolean;
begin
  hDrive := CreateFile(PChar('\\.\' + 'E:'), GENERIC_READ,
    FILE_SHARE_READ, nil, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL,
    0);
  if GetLastError <> 0 then
    MessageDlg('Error:' + IntToStr(GetLastError), mtError, [mbOK], 0);
  try
    DisableEject := false;
    if not DeviceIoControl(hDrive,
      IOCTL_STORAGE_MEDIA_REMOVAL, // PREVENT_MEDIA_REMOVAL,
      @DisableEject,
      SizeOf(DisableEject),
      nil,
      0,
      Returned,
      nil) then
      MessageDlg('Îøèáêà:' + IntToStr(GetLastError), mtError, [mbOK], 0)
  finally
    CloseHandle(hDrive)
  end;