Installed WIN 10 Pro anew from original CD. During the proces windows updates were automatically executed as well as the activation.
Immediately following thereafte I wanted to install Office 365 Home edition, for which I have a subscription.
Result: download/installation stopped at some 50%.
Since there were no other influences from other applications or interventions, this means for me that there must be a basic incompatibility between Windows and the Office installation Program.
Microsoft better finds the source of this problem and then develops a genuine solution to overcome it.
Most likely, people that numerous reported occurrences on systems that were no longer "virgin", and for which all kind of (not working) "solutions" were suggested, could be helped if MS succeeds to eliminate the mentioned basic incompatibility.