Sound issues

My friend has this crappy motherboard, and is now having sound issues with it. He hears horrible static on his end, and everyone hears the same static through his mic. After determining that it is the onboard sound of his motherboard, we are stumped on how to fix it.

Any suggestions?

Maybe a soundcard? If yes, then what kind?

If he isn't looking for a tip-top soundcard, here is one.