Worst League Glitch I've Ever Encountered.

League kills my computer.

I'm not sure what happens, but sometimes after a game ends and I click "continue", the client attempts to open and something happens. I'm not sure what happens because my monitor refuses to connect to the HDMI2 input after this glitch happens. I can't turn off my computer when this happens and of course I can't see why. So I have to force shut off and make a full recovery (1-2 hour process). This only happens as of patch 7.9. I have not changed any software since christmas, and that was just a keyboard+mouse.

If I had to guess, this glitch has to do with the fact that I'm running on Windows Vista, but I really don't know since I can't see what's happening. It's happened 4 times so far in a week. It's the most annoying thing and I'm probably just not going to play ranked until this is fixed.

This has never happened outside of League of Legends and always happens at the exact same moment (client is black and attempts to load for about 3 seconds and then my monitor 'loses signal' and my computer won't turn off).