Game Flickering Around and Causing Ear Piercing sounds

I'm new to the game and I don't know how this happened, but a loud, ear piercing sound started, and it didn't stop even if I lowered the sound volume or even muted until I unplugged my headset from my pc. The fallen turrets started flickering around and the turrets that were still up were flickering. I thought leaving would help and reconnect, but a message popped up saying that my League Files were corrupted. When it was rebooting the League files, the League of Legends sign had a different variety of colors and a lot of white in it. So I waited until the League files were clean, but it said again that the League files were corrupted. So I rebooted my pc (remember I was still in a game) and it took me awhile to get back in. I loaded the LoL client then rejoined the game, but the game finished. In the end I got an AFK punishment for something that I couldn't prevent.

Windows I was using: Windows Vista. (I'm poor ok.)