Windows 8: After update to Flash Player 13 no audio/youtube videos

Youtube videos only play a second, after that they reload multiple times and then youtube gives me some error about how it can't play the video.

Audio stopped working completely and itunes won't play songs. It's stuck at 0:00.

I already tried to reinstall. Also, I didn't find any previous versions for my windows like the mac users got.

Any help is very much appreciated. Yesterday evening the laptop did everything alright.