That mobo do you have?, the most easy way to download the drivers is from teh manufacturer web of the mobo or sound card.
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"Two things are infinite: the universe and human stupidity; and I'm not sure about the universe.". Albert Einstein.
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Reply to saint19
If there isn't a W7 driver on the manufacturer's website (which could be why you are having issues finding it), try a Vista driver. But only give this a go if it is a standalone sound card (i.e. there is an actual card for sound in your computer).