Hmmm. Very strange. I have two installation of M3 64 bit. First - on my desktop PC and it shows those windows in the bottom-right corner, as pop-up windows which fade after ~10 sec (exactly as You wrote).
And the second installation, on my laptop. Both installation were made in just the same time (almost). In case of laptop there is the bottom-right corner info window, which fade after 10 sec, but additionally i have - i think - the kind of plasmoid (?) in upper left corner of screen. For example, after copying 10 files, i have 10 full transparent background windows in form of column from top to bottom. Such windows are still, so it is necessary to close it one-by-one, manually.
I dont know how it was done by me during configuration

Any idea how to turn it off?