Is the front audio option activated in the BIOS ? If not, simply enable it and it will work. (You'll probably have to choose between AC'97 and HD Audio)
On the front audio connector itself, is it written AC'97 or HD Audio ? You must enable the correct option in your BIOS.
Also, is the front audio connector of your case connected to your motherboard ?
Do your speakers work, or, for that matter, if you plug your headphones in the motherboard backpanel itself, do they work ?
If you have no audio whatsoever, it's probably a driver problem. Simply unistall it, then reinstall the newest version.
Hope this helped,