Black screen + Task Bar bug.

I have recently had this issue with league. About 2 or so weeks ago, I hit alt-tab in a game of league to change some music that was playing on Spotify. When I hit alt and tab again to go back into league I was met with a completely black screen and my task bar. No matter what I hit, the screen was black, and I could hear league, but couldn't see it. I tried hitting the other applications pinned to my task bar, it showed them open (the little blue bar below the open apps was there), but I still only saw a black screen. (I hit Skype and I could hear the opening sound of it, couldn't see it though) I even tried ctrl+alt+delete, and it did pull up the screen, I then hit task bar. Same thing happened, it was open, I just couldn't see it, still black. I have to restart the computer each time. Due to this, I am now the AFKer of 2 ranked games, and multiple norms.

Please Help! Hutch