Computer Hard-Crashing at the End of a Match

So three games in a row so far my computer has completely frozen up, and it only happens right at the end of a match where the victory/defeat logo pops up with the button to "continue". I've noticed that it happens the second I click "continue" where it would normally take me to the "honour a teammate" page. I'm not sure what the issue could be, but it started last night. Played two more games with the exact same results. The match would end, I'd click "continue" and my computer just completely freezes up and the only way to get around it is to force-shut-down my computer. This can't be "healthy" for my PC to keep freezing and shutting down.

Would anyone know what might be the cause of it? I've been told that it could be a corrupt hard-drive causing the crashes, but the thing is, I actually had to remove one of my older hard-drives due to a similar issue that the League Client was causing a couple months ago (hard-freezing) so I reinstalled League onto one of my other hard-drives and that fixed the issue at that time. The game is currently installed on that new hard-drive so it couldn't be corrupt so quickly (its only a couple months in use).

Any ideas?

Edit: PC just froze again as I was opening a hextech chest. What the f*ck is going on?