Here is what they say>
Audio Card Drivers
OPTi sold its audio chipset business in 1997. Please keep in mind that even prior to 1997, OPTi never made sound cards. We previously sold chips for these cards to other companies, who are responsible for providing and updating drivers. OPTi does not offer any audio drivers. If you need technical support or drivers, you will need to contact the company that made your sound card.
This means We need to know the maker of the sound card, and check their web site for updated drivers.
Here is the link to the fcc site that can help you find out who made it. You need to look on the card and find the fcc id # and plug it into this website
http://www.fcc.gov/oet/fccid/