Hey, so this problem started to happen recently, whenever I alt tab in TF2, there is a little white box with text in it that shows up on the top left of my screen, it says Team Fortress 2, and I cant click anything on my screen, when I try to go back in game nothing happens, I tried ctrl alt deleting, task manager, everything, so my only alternative is restarting my computer, its really annoying, plz something help