[CRASH] Game Window Never Launches

When starting any summoner's rift game (it may also happen in other game modes but I'm not sure), the game window does not launch after champ select ends. I have to Ctrl-Alt-Del and terminate the League of Legends.exe process and then click the "Reconnect" button to get the game window to launch. Sometimes even that doesn't suffice; I have to do it multiple times to get access to the game.

This is a serious problem, as it can sometimes cause me to not join the game until 1 minute or even 1:30 into the game, setting our team back from the very start.