In the Start Menu search box type in: update drivers
and choose Update Device Drivers. When the Device Manager screen opens find your Sound, Video and Game controllers section.
In there choose your audio/sound device and right mouse click, and choose Update Driver Software. Let it search automatically. It should pull a driver off the internet for you.
No, doesn't come and go in waves. I got the sound working one night, and the next day (after having shut down for the night, I think I even moved the speaker plug into other ports trying just to see) and the next day I couldn't get the sound back.
I'll try this trick when I get home tonight. I dislike letting the computer do the thinking for me, but I guess since the driver off the manufacturers page isn't working, it's time to go to plan b.
I'll let you know how it goes.