Gamebreaking Yasuo Computer Crash Bug

Every time I play , League of Legends freezes when the game starts, I can see only 4 health bars, and all the GUI is fine, but with the numbers missing. The updated Summoner's Rift music plays in the backround. The game doesn't budge until I Alt + Tab, and when I do my whole screen goes black except for my taskbar and my cursor (Still the Gauntlet cursor from the game) I can Ctrl + Alt + Delete, but if I open my taskbar i cannot control it, because of the black screen forcing itself to move forward above any other program. The windows key doesn't work, and I am finally forced to shut down my computer by holding the power button. I assure you this is not a problem involving my computer, because this happened on my old computer and this new computer multiple times. When I reconnect to the game, it's already been a 15 minute 4v5 and we usually lose. This ONLY happens when I am playing .