When I added my 2nd HD to my dell, I had to go into bios (F2) and select the hard drive location (from off to on i believe). Once I did that, all was good - format, then use.
However, my HD did no show up until I did that. Your problem may be different.
FYI. Good Luck.
I have checked the wires and I see it in the bios....It has been turned on in bios but not able to to see it in Xp to format ... Though it does show up in the Device Manager ... maybe adiferent problem?