Thank you for your reply. But as I said: A fresh installation of the whole computer didn't help, so it doesn't seem very likely that a repair installation of Office could be a permanent solution?
It seems to an incompatibility issue, not a faulty installation.
Anyway, as a native German speaker I posted the same question in the German HP forums where someone finally provided a solution:
You need to disable the "Printer Status notification" under "Installable Option" somewhere in the printers/drivers settings.
(Can't exactly tell you the path because I don't know how the different buttons are named the English Windows)