Please someone help. I can find anyone who has had this issue. All of my Audio drivers are missing!! I did not have any external speakers hookup up to the MacBook Pro. All I did was try to install Joost (which didn't work) and then all sound was gone. I have attached a picture of the missing drivers. I cant imagine that a software program could actually fry the hardware. Please someone tell me they can help! Btw I have tried an archive and install to no avail.