If it turns out that your Windows sound output has been muted, be certain to ask your computer guy if there is a key or key sequence on your keyboard you can hit to unmute it (or to try to unmute it).
On my HP laptop, where I've turned off the "Quick Function Keys" feature so that I have access to the F keys "as God intended," the F6 key is the mute/unmute toggle. F7 is decrease volume and F8 is increase volume. All of these only serve those functions if I'm holding down the Fn key plus the previously noted key together. What's nice is even if the sound is muted, if you attempt to either increase or decrease volume it will unmute the sound as part of that.
Brian - Windows 10 Home, 64-Bit, Version 1803, Build 17134
After all, a democracy based solely on the values of the majority, with no overriding ethical principles and processes, is nothing more than clubhouse democracy, great for those on the inside and a tyranny for those who fail to see eye to eye with the majority.
~ Paul Noeldner, May 16, 2007