Thanks.

Using Insert-Picture is slightly complicated in my case due to the complicated folder structure of the project. Opening several locations in several explorer windows simultaneously and using drag-n-drop was the fastest solution.

A macro capable of deleting all alt. texts for all objects in the document would be perfect, if I have had one :) I will try writing it.

Coming back to my original question, do I understand you right, that there is NO option to turn off the discussed drag-and-drop behaviour?