You have 2 options:
- Install the *latest* "Platform/nForce Drivers from nVidia:
- Install the latest ALSA drivers from the Alsa Project:
Both options work more or less right... actually I'm stil trying to find the difference
If you look arround in this forum you'll find a couple of "how-to's" as regards installation.
I don't know if this apply to all the nForce2 mobos, but mine (a7n8x deluxe) has a problem with the center channel, wich "jumps around" sort of aleatory to any other speaker