I need help with audio driver downloads please!?

I have a sony vaio desktop vgc-rb30, orginally came with windows xp and crashed so I had windows xp pro installed and I now have no sound. I went to sony esupport and it was no help. I tried to download the driver they suggested and it tells that it can not find audio device info. I am also missing the icon for volume at the bottom of the screen. There is no audio device showing in my device manager under sounds and what not. This is all it shows: audio codecs, gameport for gamecard 3, legacy video capture devices, media control devices, video codecs, unimodem half duplex audio device. When I right click on any of these to update it says they are already updated. I dont know anything about these things. I read things about sound cards and dont know those either. If anyone can help it would be greatly appreciated. Thankyou