Techs Door

Aero Desktop Preview: A small button at the absolute bottom right of the screen. If you hover on it, all the windows will be invisible & you could have a look at the desktop.

Disabling this option is quiet easy. Right-Click on that button and click Peek at Desktop option to uncheck it. That’s it.

But, if this does not work for you, Open Registry Editor (type regedit in start menu search and press enter) and go to:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced