Tried that. It uninstalled the drivers
, and, after a restart, a pop-up indicated that the drivers were (re)installed. Still no sound. I unplugged the speakers, and that was accompanied by static in the speakers and very brief 60Hz hum. So I know the speakers are working. My rig has an EVGA 780i 3-Way SLI motherboard. I have no separate sound card. There is a cluster of 6 mini jacks in the back -- the green one is where I was plugged into (and have been since I owned the machine), but I plugged it into the other jacks, and still got nothing. Left it plugged into green.
I fired up a YouTube video and noticed on the main Volume Mixer control that Internet Explorer is getting sound (there's a volume bar -- pseudo VU meter -- pulsating). System Sounds is off (as expected), but device Speakers is also pulsating.
Any more suggestions?