[marcoszorrilla]

Código Delphi [-]
interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls,ShellApi,ShlObj;

    procedure ExitWindowsDialog(Handle: THandle); stdcall; external 'shell32.dll' index 60; //API declaration
....
procedure TForm1.Button1Click(Sender: TObject);
begin
  ExitWindowsDialog(Handle);
end;