Help! Game crashing to desktop, client disappears.

I can log in to League just fine, and start a queue. But once the clock in champion select counts down to 0, my client disappears, even though it is still running in my task manager. So I close the client via task manager, and re-login. Once I re-login I am promted to reconnect to the game I just left, but when I click reconnect, the client just disappears again and I am left staring at my desktop background. THE CLIENT IS STILL RUNNING IN TASK MANAGER THOUGH. I cannot reconnect or get to the loading screen at all.