So I turn on my PC today and I noticed a starnge bar in the top left corner. I had never seen it before and was not there last night when I turned my PC off. I then notice I ahve no sound and the sound icon on the bottem right hand side onf my PC says it is muted. I go and bring up the sound menu and sure enough everything is muted, I try to unmute it and Windows wont let me, I turn the sound up and it automatilly brings it down. I ahve checked for viruies and maware, nothing. I am stumped and very annoyed. Help