|"And the HDD is SCSI IDE"|
I highly doubt it. It may be reported as such, but it's SATA. All you had to do was check the specs:
And as I said, if you can't change the BIOS setting to "IDE mode", you will have to create a new XP CD that includes the SATA driver. The drivers may be a bit difficult to track down because Toshiba only has drivers for Vista. That means you will have to identify the SATA controller used on the motherboard, then search for the appropriate drivers.
Resolving "Setup did not find any hard disk drives" during Windows XP Installation