You are talking about long past, and the DocuWare Windows Client which has long been dispensed with.
DocuWare Web Client does not invoke any local app to view a file. If you wish to open such a file - zip, mp4, avi, etc you need to select Edit from the result list or viewer. Then the file will be downloaded and opened in the default application for that file type.
It is worth keeping in mind that all supported file types are rendered to a png image for displaying in the viewer. You are not looking at the native file.
Senior Director Support Americas