XP not detecting sound card

Hi,

I have Panasonic CF-29 that I am trying to fix for my sister. There is no volume. XP does not recognize a sound card. I am not sure if the laptop has a sound card. I never opened up a laptop case. So I prefer not to open the case unless I have to. I bought an external sound card and XP doest recognize it. My PC recognized the sound card. I connected a USB mice and an IPod and XP didn't recognize it either. So there is a problem with USB port. According to ITunes, the previous owner connected their IPod 2 months ago. So the UBS port was working 2 months ago. Any ideas? Will an internal sound card fix the problem? I already updated the chipset. And uninstalled all the devices under USB System controller in Device Manager.