Go to
www.americas.creative.com and choose the SUPPORT -> AUTO UPDATE. Make sure you are using IE as it does not work with FireFox or NetScape.
There are several driver updates and EAX updates for the audigy series cards to make sure they work flawlessly in new games. Don't trust just going to the site and downloading what you think you need. Let the site do all the work for you.
I have an Audigy (1) Series card as well, the Gamer and needed to do this for my card to work properly (otherwise, it didn't detect or use EAX 1/2 the time, and if hardware was forced it would crash).
EDIT: As for the onboard sound, disable it in the BIOS to free up system resources
