Thanks very much, ARC1020, for your elaborate and clear reply. You are right, your problem is a bit different. In the meantime, I fixed my problem with the help of the Microsoft chat help desk. They...

Thanks essenbe! In the meantime, I fixed it with the help of the Microsoft chat help desk. They told me to go back to the previous version of Windows. Apparently, they blamed it to a faulty update...

All of a sudden the following symptoms (all at the same time)::
1. Taskbar icons gone (replaced by a neutral identical icon) except Edge and Store
2. In File Explorer, no longer thumbnails, no...