Why Won’t My Sound Work?

I have recently reinstalled Windows XP Media Center Edition and I’m having trouble getting my sound to work.

I have an eMachines Desktop computer (model: W6409) and the sound card is built into the motherboard.

I have checked out both:

http://downloadcenter.intel.com/Product_Filter.aspx?ProductID=2367
http://www.emachines.com/support/product_support.html?cat=Desktops&subcat=W-Series&model=W6409

And after installing every single driver, nothing works. They install successfully (I think) but they don’t show up in the Device Manager.

So what should I do?

EDIT: Nevermind, I fixed it.