@MontereyJack,
Yes, did that. Also updated drivers. I've come to the conclusion that I have a bad sound card. Phooey!
By the way I have had my computer do the same as you describe. It seems to have a mind of it's own and unexplainedly mutes the sound but that's not the case this time.
Oh well..... I intend to build my next computer so at least I know where the different parts are located. I consulted with a friend who does cheap house calls so I should have it fixed in short order.
Thanks for your response.