function MyWaitFor(Event: THandle): Boolean; // von negaH: [url]http://www.delphipraxis.net/post696510.html#696510[/url]
begin
  Result := False;
  while not Result do
    case MsgWaitForMultipleObjects(1, Event, False, INFINITE, QS_ALLINPUT) of
      WAIT_OBJECT_0:
        Result := True;
      WAIT_OBJECT_0 + 1:
        begin
          Application.ProcessMessages;
          if Application.Terminated then Exit;
        end;
    else
      RaiseLastWin32Error;
    end;
end;

constructor TDownloadUpdate.Create(aFilename, aURL: string; aFinishEvent: Cardinal);
begin
  inherited Create(True);
  fFile := aFilename;
  fUrl := aURL;
  fFinishEvent := aFinishEvent;
  FreeOnTerminate := True;
  resume;
end;

procedure TDownloadUpdate.Execute;
var
  www: TIdHttp;
  fs: TFileStream;
begin
  inherited;
  www:=TIdHttp.Create(nil);
  [url]www.Port:=81;[/url] // Nur testweise, da Apache auf 81 lauscht.
  try
    try
      ForceDirectories(ExtractFilePath(ParamStr(0))+'\Updates\');
      fs:=TFileStream.Create(ExtractFilePath(ParamStr(0))+'Updates\'+fFile, fmCreate);
      www.Get(fUrl, fs);
    except
      //
    end;
  finally
    [url]www.free;[/url]
    fs.Free;
    SetEvent(fFinishEvent);
  end;
end;

procedure TUpdater.DownloadUpdate(i: Integer);
var
  Event: THandle;
begin
  Event := CreateEvent(nil, False, False, 'ThreadFinished');
  TDownloadUpdate.Create(GetUpdateInfo(i, 'filename'), GetUpdateInfo(i, 'url'), Event);
  MyWaitFor(Event);
  CloseHandle(Event);
end;