Sub haslo()

Dim sciezka As String, plik As String
  
With Application.FileDialog(msoFileDialogFolderPicker)
   .Title = "Wybierz folder"
   .InitialFileName = ThisWorkbook.path
   If .Show Then sciezka = .SelectedItems(1)
End With
   
If sciezka <> "" Then
plik = Dir(sciezka & "\*xls")
Application.DisplayAlerts = False
Application.EnableEvents = False
Application.ScreenUpdating = False
Do
If plik <> "" Then
    Workbooks.Open plik
    Workbooks(plik).SaveAs Filename:=plik, Password:="Trebor"
    Workbooks(plik).Close False
        Else
            Exit Do
                End If
plik = Dir
Loop
            Application.DisplayAlerts = True
            Application.EnableEvents = True
            Application.ScreenUpdating = True
End If
End Sub