File Manager Pops Up On It's Own While I Was Sleeping

Today, while I was sleeping at the computer, the mouse fell on the floor and woke me up.
It turned out that when I right click on the desktop, the first item is “Open in New Window” which opens up the file manager! So, it must have happened when the mouse hit the floor.

3 posts were split to a new topic: Users can still delete the original post (when no replies are given)

Sven’s reply is the solution.