This is probably not it, but I know when updates go out for our OS, all the pc's on our network have to be reconfigured. Meaning i have to reassign which jack does what. Also, check into Sounds and Audio devices from the control panel. Frequently this defaults back to mute whether you chose it or not.
I checked Sounds and Audio devices and everything is as it should be. The mic is even being recognized, just no sound.
This one really has me stumped. I deleted both sound devices from the device manager and had the drivers reinstall. Still nothing. My mic was working without a hitch for months, then suddenly it's not. Like I said, I would have chalked it up to hardware failure if the same thing didn't happen on my wife's laptop. I checked it with a different headset and the same thing, mic is recognized but no sound.
I also tried a system restore to when it was working, that was no help either.