Which audio driver to download depends on your sound hardware.
1) Are you sure that it is a driver problem?
2) What do you see in the Device Manager? Any yellow question marks or exclamation points?
3) What kind of sound hardware do you have? Make and model of your PC, plus whatever you can see for it in the Device Manager. Right-click on My Computer, select Properties, go to the Hardware tab, click on Device Manager, open Sound, Video, and Game Controllers, and let us know what it says about your sound device.
Question: Do you mean XP Service Pack 2? There is no XP2, so I just want to make sure I understand what you mean.