Anyone Else getting locked out of League?

Not sure if this goes here, but I'm experiencing instant crashes of League of Legends when I load onto SR.

I've tried uninstalling and reinstalling, doing several reboots, and even making sure every driver on my comp is up to date, but it doesn't change the fact that when I load onto SR, my computer instantly overheats its fan (probably draws more resources than my CPU can handle), and forces me to do a hard reboot by locking my mouse and keyboard out of issuing commands to the computer.

I've been playing on the same computer with the same settings for nearly two and a half years, and it doesn't make much sense. Any advice?