Как выключить компьютер с любой версией Windows

Просто воспользуйте следующим кодом:

function GetWinVersion: String;
var
   VersionInfo : TOSVersionInfo;
   OSName      : String;
begin
   // устанавливаем размер записи
   VersionInfo.dwOSVersionInfoSize := SizeOf( TOSVersionInfo );

   if Windows.GetVersionEx( VersionInfo ) then
      begin
         with VersionInfo do
         begin
            case dwPlatformId of
               VER_PLATFORM_WIN32s   : OSName := 'Win32s';
               VER_PLATFORM_WIN32_WINDOWS : OSName := 'Windows 95';
               VER_PLATFORM_WIN32_NT      : OSName := 'Windows NT';
            end; // case dwPlatformId
            Result := OSName + ' Version ' + IntToStr( dwMajorVersion ) + '.' + IntToStr( dwMinorVersion ) +
                      #13#10' (Build ' + IntToStr( dwBuildNumber ) + ': ' + szCSDVersion + ')';
         end; // with VersionInfo
      end // if GetVersionEx
   else
      Result := '';
end;

procedure ShutDown;
const
  SE_SHUTDOWN_NAME = 'SeShutdownPrivilege';   // Borland forgot this declaration
var
  hToken       : THandle;
  tkp          : TTokenPrivileges;
  tkpo         : TTokenPrivileges;
  zero         : DWORD;
begin
  if Pos( 'Windows NT', GetWinVersion) = 1  then // we've got to do a whole buch of things
     begin
        zero := 0;
        if not OpenProcessToken( GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES or TOKEN_QUERY, hToken) then
           begin
             MessageBox( 0, 'Exit Error', 'OpenProcessToken() Failed', MB_OK );
             Exit;
           end; // if not OpenProcessToken( GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES or TOKEN_QUERY, hToken)
        if not OpenProcessToken( GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES or TOKEN_QUERY, hToken) then
           begin
             MessageBox( 0, 'Exit Error', 'OpenProcessToken() Failed', MB_OK );
             Exit;
           end; // if not OpenProcessToken( GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES or TOKEN_QUERY, hToken)


        // SE_SHUTDOWN_NAME
        if not LookupPrivilegeValue( nil, 'SeShutdownPrivilege' , tkp.Privileges[ 0 ].Luid ) then
           begin
              MessageBox( 0, 'Exit Error', 'LookupPrivilegeValue() Failed', MB_OK );
              Exit;
           end; // if not LookupPrivilegeValue( nil, 'SeShutdownPrivilege' , tkp.Privileges[0].Luid )
        tkp.PrivilegeCount := 1;
        tkp.Privileges[ 0 ].Attributes := SE_PRIVILEGE_ENABLED;

        AdjustTokenPrivileges( hToken, False, tkp, SizeOf( TTokenPrivileges ), tkpo, zero );
        if Boolean( GetLastError() ) then
           begin
              MessageBox( 0, 'Exit Error', 'AdjustTokenPrivileges() Failed', MB_OK );
              Exit;
           end // if Boolean( GetLastError() )
        else
           ExitWindowsEx( EWX_FORCE or EWX_SHUTDOWN, 0 );
      end // if OSVersion = 'Windows NT'
   else
      begin // just shut the machine down
        ExitWindowsEx( EWX_FORCE or EWX_SHUTDOWN, 0 );
      end; // else
end;