Check Device Manager for any driver issues (shown by an error symbol in the devices list).
Even if there are no errors you should check Creative Labs website for the latest driver for your Audigy 2 ZS. The correct page is here: Creative Worldwide Support > Audigy 2 ZS
Even if there are no errors you should check Creative Labs website for the latest driver for your Audigy 2 ZS. The correct page is here: Creative Worldwide Support > Audigy 2 ZS