Проверяем, пустой ли каталог

function DirectoryIsEmpty(Directory: string): Boolean;
var
  SR: TSearchRec;
  i: Integer;
begin
  Result := False;
  FindFirst(IncludeTrailingPathDelimiter(Directory) + '*', faAnyFile, SR);
  for i := 1 to 2 do
    if (SR.Name = '.') or (SR.Name = '..') then
      Result := FindNext(SR) <> 0;
  FindClose(SR);
end;

Пример использования

procedure TForm1.Button1Click(Sender: TObject);
begin
  if DirectoryIsEmpty('C:\test') then
    Label1.Caption := 'empty'
  else
    Label1.Caption := 'not empty';
end;