OptiPlex 320 Running Windows XP Professional - No Sound. My computer required a new hard drive, so I bought one and reinstalled Windows XP Professional and now I have no sound. I have gone to the Dell Site and downloaded all of the necessary drivers, but the computer will not recognize the drivers. Also, instead of the drivers being .exe files they are .ios files. How can I get my computer to recognize the drivers I have downloaded from the Dell site?