SATA or EIDE, when you add a drive it is not partitioned or formatted.
XP will not assign a drive letter.
Go to Control panel -> Administrative tools -> computer management ->
See if the drive shows there. It will not have a drive letter. You can partition and format it right in that screen.
my two sata drives show up in the boot sequence, but win XP only recognizes one.
Windows XP Pro, SP2
ASUS A7N8X-E deluxe MOBO
AMD Athlon XP 3200+ Processor
two Seagate 250Gb sata drives