Many PC's you get these days with Vista preinstalled don't really support XP anymore, it is hard if not impossible to get the necessary drivers. Also some manufacturer's have pretty no support, Sony belongs at the very top of that list. I'm afraid you'll have to try the different drivers until you find one that works, good luck!
Sometimes your best choice is to first restore the system to factory defaults, and then run a tool like SIW (
http://gtopala.com) which will allow you to save all the driver info into files. And then you can try to find the correct drivers for XP for your hardware.