Sound issues? Youtube issues?

Basically, it seems when I have skype or steam open my sound goes crackly or it doesn't work at all. Youtube videos refuse to load sometimes and so do itunes songs. I don't want to have to exit my steam and my skype, the problem originated with minecraft, where when playing the game my sound got crackly. It's gotten worse and it's very annoying. My speakers also do not work for unknown reasons, so maybe this is connected?
With the youtube videos, it either refuses to load followed by an error screen or it plays with no sound. Please give short and simple answers as I'm not technically well spoken.

Make sure you are using Adobe Flash 11.9.900.170
when you are playing a youtube video, just right click on the video
the last item on the list should be an "About Adobe Flash" click it, and upgrade your Flash.

if your speakers have an intermittent problem, then try plugging your speakers into a different computer, or try plugging in different speakers to your computer to test.
you could have a bad wire.