Help I have Dimension XPS T500 with PIII processor at 500MHz it already has a 12 GB hard drive running WIN ME I want to to swap this hard drive for a 40 GB.

This drive already has WIN XP PRO installed on it and is already partioned I was running it in another computer but now want it in the T500. When I first installed it it was not seen at all, after messing about with the bios it now sees it but fails to boot. I have also tried updating the bios from A07 to A11 but to no good. The hard drive is a Maxtor DiamondMax Plus 8 ATA/133.

I have read some where that I might need a PCI card with the appropriate ATA 66/100 interface on it. If so what is it and how do I go about it?

Any help would great even if only pointed in the right direction, thanks.