Oh, Windows XP (old version) setup doesnt offer driver for SATA drives. So, its better to use XP- service pack rather than unpatched versions...
If you dont have one, try the following :
1. Get a disk and load the sata driver for your harddisk (you can get it from sony or from hdd manufacturer)
2. In the setup screen, Right after the "Press any key to boot from CD" screen, it says something like
press F6 to load additional drivers. Press F6, and it will keep going.
Put the disk and it will be read...
3. Thats all.....
I hope it works for you.... Please let me know..