Screen refuses to fullscreen ingame, taskbar covering the bottom,impossible to play a game properly

This only started yesterday after I updated to 5.22. I was in a game and ALT+TAB'd out to answer a skype call and then all of a sudden the game went out of full screen and onto my home page. My taskbar is covering my HUD, and in game my mouse refuses to pan. Pressing Y doesn't do anything, the only that I can do is constantly press spacebar to keep the camera view on my champion. I've tried closing my client and restarting but to no avail. And yes, the full screen button is greyed out, next to the minimize and exit button in the top right. This happens every game and it is pretty much impossible to play a game normally so it looks like I won't be able to play until it's fixed. I put a link to the screenshot in the "link" part but it's not showing up for me so here it is again just in case; http://imgur.com/O5R0ghO