Shoutbox

I would suspect you have a SATA chipset that requires a third party driver with XP (pretty much all of them other than integrated SATA of Intel mainboard chipsets).  You will need to press F6 during Windows XP setup and insert a floppy with the appropriate driver.  Since your computer appears to be a laptop, chances are you don't even have a floppy drive -- and that is the only supported medium. 

You will probably be best off just learning to live with Vista.