Sound Problem

Hello,

So, I recently had this terrible bug on my computer when it said "No Output audio device installed" without myself doing anything for this to happen, after following MANY tutorials I stumbled upon one that worked, partially. So, now I don't have the cross in the sound area and everything ?should? work, but it doesn't. I can't hear ANY sound except for when I log into skype and I get that usual skype login sound. Other from that, nothing works.

HELP :C