I have the same problem, same sound card as well, on board sound cards suck. Thats what your problem is. Two ways to fix this. Upgrade to winxp, XP will correct the issue. Or reinstall your motherboard software which has the software to your sound card.
This is what helped me, I recommend getting WINXP it runs the game better, if you have WINXP already just roll back the driver and you should be fine.
This is my opinion and it worked for me, There probably is another way.