If you followed all the advice above and still cant find a cure, I might have another suggestion for you.
1. First be sure that you are not sharing ports in the front and back. The green port in the back is the same port thats used as a headphone in the front. The same goes for the pink microphone jack. So be sure only ONE of these (either the front or the back) is in use.
2. If no sound comes from the front jacks, go into "Reaklek HD Audio Manager" and in the "Audio I/O" tab click the little wrench button next to the word "Analog."
3. In this setting, CHECK "Disable Front Panel Jack Detection."
4. Click OK and suddenly you should be hearing audio and recording with your mic from the front jacks.
Solution for me :
Go to device advanced settings located at the right hand corner of the screen in realtek hd audio and make sure the ''mute the rear output device, when a front headfone plugged in'' is highlighted this has solved my problem. I stayed up from 11pm to 2:42am trying to figure this out.............. never ever mess around with buttons in realtek hd audio manager.
Goto Realtek Audio HD manager in systray
goto AudioIO tab and see where is the headphone/speaker symbol
There should be only one such symbol depending on where u have connected the headphones(front/rear)
If you find headphone symbol repeating at some other place, change it to something else
Now everything will work
/HD audio driver isnt working via headset/
I had the same ploblem, (no sound via headset, but the speakers are working) used by xp prof, and I cant solve it. There was time, when everything was fine, headset and speakers are worked but I dont know why (i didnt install anything) the speakers worked fine, but the headphone jack is "cutted off". Uninstall/install the asus drivers but nothing happened.
Important thing! When the laptop starts there is a sound (ASUS something) that sound come out from the headset!!! But under the super windows no sound.
Same results as when I plugged the microphone the computer sign that one jack plugged/unplugged, but the headset jack isnt working.
I visit the asus website there was a hint "go to asus service" very good.
Finally (before I go to the asus service) last chance I put a win7 to my laptop (ASUS F3SG) at the first time the results was the same no sound via headset. But I find a new driver on the realtek site Vista_Win7_R2 40.
Now everything is working fine.
I hope it helps to somebody because I almost lost my mind.