@ian-coog thank you! Yes, this could be the cause of the problem. In my case, probably the updates of win7 that happened inbetween (since my first signalling of this problem, one month ago) possibly solved this problem.
Otherwise, there are no reports of things like a browser which does not update correctly in win7...
I have no idea if the system update problems could be also the root of a browser update problem.
I use win7, not win10, but it seems that it happens also in win7, even if the two articles you kindly cited are mainly showing the methods to solve the problem for win10.
Anyway, I posted my experience here, just in case someone else is looking for the same symptoms.