Ingame bug

Couple days ago i started 1 aram. I got anivia that game and everything was clearly nice before game started. After loading screen game started and i was like lets buy items, i clicked on map to move my champion and my screen went to desktop and it showed me like i clicked windows button like this http://prntscr.com/72a6h3 . And i tryed to go back in game by Alt+ tab and again this happend it showed this http://prntscr.com/72a6h3 and its happening every time. I repaired lol it happens same when i specate someone. This bug happens after new windows 10 update... Sorry for my bad english i hope you uderstand me.. I really need help