Hi
I assume you didn’t include the SATA driver to the Win XP CD.
The point is that Win XP needs a additional SATA driver in order to be able to recognize the HDD which is connected to the SATA controller.
Here is a nice FAQ from the Toshiba Europe Support Knowledge base:
http://aps2.toshiba-tro.de/kb0/TSB85017Z0000R01.htm
You should check your chipset and should download the Intel Storage Manager driver from Intel page which would support your chipset!