http://www.esstech.com/techsupp/drivers.shtm

Try that site. Find your driver for the sound model you mentioned. I would suggest giving the NT drivers a go, as well as the 98/Me/2K drivers. If the driver upgrade does not work, have you tried a reformat? It could be that you have a corrupt installation of XP.
If I think of something else I will definitely post it up.
BB