by boco » 02.07.2013, 18:47
Even if the updates are pulled from your WSUS, some service and supplementary files must be downloaded from other places, still. The core of WSUSOU, the wsusscn2.cab catalog, for example, must be downloaded from Microsoft itself since it isn't present on your WSUS (WSUSOU fails to work without that file). The optional downloads aren't on your WSUS, either, but can be unselected.
It is not possible to run the downloader completely offline! The ''Offline'' only means the installer.
Microsoft update catalog: http://catalog.update.microsoft.com/v7/site/
Windows Install media download: https://support.microsoft.com/en-us/help/15088/windows-create-installation-media