forums.wsusoffline.net

Has anybody successfully used WSUS offline to download the updates but then managed to extract the downloaded updates and import them into your offline Microsoft Windows Server Update Service? At the moment it looks like you use the app to download the updates and then use the app to perform the updates.

That's how wsusou's WSUS implemetation is designed to be.
wsusou supports downloading updates FROM a WSUS server.

Exporting wsusou's updates to WSUS has to be implemented by MS.

I have a little different question instead. I know (correct me if I'm wrong) that your software cannot retrieve ALL the windows and office updates (in fact after applying it several updates from microsoft online still remain), but the WSUS Windows server does. Could I use in some way your software to let it install also the downloaded updates from a WSUS machine so that the computer will be fully updated only executing yours? The WSUS updates are stored in shared folder in our network, so they are easily retrievable.
You could ask: why don't you use directly the WSUS server? It's not so easy, we do computer reparations and our bandwidth is poor. I cannot insert in a domain every computer that I need to update. So I found a way modifying temporarily some registry items to drive the windows update to the WSUS server, but with windows 10 it doesn't work so well and often the pc works with online classical updates saturating our bandwidth. So if I could do all the updates with your software which could install also the original WSUS downloaded items it would be great.

Hope to have been clear enough
Thanks

MS does not provide any possibility to determine all update. The only catalog they provide to the public is wsusscn2.cab, which just contains security-relevant updates.
It is currently not possible to implement the API WSUS uses to determine the updates. But it is possible to download the updates (determined from wsusscn2.cab) from your WSUS instead of MS.
The user Cababs created a list of optional updates not covered by wsusou: viewtopic.php?f=2&t=4182

Using WSUS to determine the updates required to install is technically possible (by modifying .\client\cmd\ListMissingUpdateIds.vbs), but I never worked with WSUS and the VBScript-API. A possible solution may be a similar to the current way, but using "ServerSelection = 1", instead of "3". But I currently don't know, how to feed the WSUS URL to WUA.