It works! It finally works!!
More particularly the integrity check system did its job as designed, including giving out right from the start a conclusive clean bill of health where its recovery process had yet to start and was going to need more than half an hour to conclude with succes.
I did not realise that the missing executable had to be delivered through the update system, which takes an awful lot of time as we all experience.
So mr/ms admin you were right, I was wrong and reminded to not take every message for granted.
By the way, larrylynx, my copy is LEGAL. Not so sure of my ATPL tough...
Thanks everybody and best wishes.