|FDISK is a dos/windows 9X/ME partitioning tool. You don't use it for XP. As a matter of fact I don't think it's even on the XP disk so you must be using some other disk. And I'm not sure how fdisk sees SATA drives anyway.|
Just boot up with the REAL XP installation disk (you may to use the F6 option to install SATA drivers) choose to install XP, remove any partition you've already created and then repartition.
Oh and you'll need at least SP1 in order for XP to see the entire 500 gig.
You're not really green until you're soylent green.