Hi Lorenzo welcome to the forums.
Do you mean when you mouse over the thumbnails, that, it is not showing the open window on the desktop?
Show only little preview but not open windows on desktop.
I try to check all option in Option folder under visualization tab.
Last edited by Lorenzo Farina; 30 Aug 2015 at 05:15. Reason: Add some other info
I just looked too, but didn't see anything. Does clicking the thumbnail at least bring the window to the front or to the desktop?
Oh! I just thought of something, you might want to check your settings in "Ease of Access" too.