[CRASH] "Continue" Crashes My P.C.

Hello!

I am currently having TWO issues with my League of Legends Client!

#1: When I start up League, after I hit "LOG IN" after inputting my information, my computer will freeze for anywhere between 5 - 20 seconds. If I have my headphones on, I'll hear a beep and then the launcher will pop up, but load all the information very slowly although I can hit "Play Now" right away.

#2: From time to time, after I finish a game and the Victory/Defeat game pops up, I hit "Continue", monitor turns black and nothing. If I'm playing music, I'll continue to play music but I can't alt tab and go back to desktop, so I'm forced to restart my computer.

Please halp =(. Sometimes I can go on for 4 games in a row then it'll crash, and sometimes it'll be my first game where it crashes.

I've updated all my drivers and I've tried running League as an Admin as well.

Thanks for your time!