how to install audio driver on computer?

i assembled a computer last week .after i install windows xp i tried to install chipset, audio drive ... but audio driver can not be installed.i download another audio driver for realtek audio driver from internet ,but it is still the same .i dont know is the mother board is broken or cd is corrupted.the mother board is asus M2N-MX SE PLUS
and audio driver is realtek audio driver.