New computer and HD problems

Bought a Hp DC7600 - Pentium 4 3.00 GHZ. Its used but it has more
horse power than the one I'm replacing. Problem I'm having is that the
new/old computer doesn't want to regonize the Hard drives from my old
computer. On the old computer I was running Windows 7 - 64 bit. I
thought that I would just be able to swap the hard drives ; let the
computer discover and install all the new Hardware and I would be a
go. ( At least that is how I did it in the good old days ).
I have three hard drives that I want to swap. A 160 Gig with Windows
7; a 500 Gig with Windows XP ( both these are IDE drives ) and a 1
terabite Sata drive. The I terabite is recognized by the Bios; however
in windows XP it shows as only 128 Gig; this is in the computer
management componet; as if I try to open via Windows Explorer; it
tells me that the drive needs to be formated.
The other two drives would not show at first. I than changed their
order on the ribbon cable and was able to boot into the start up
screen of Windows Xp at which time the computer would re-boot and the
cycle would start all over.
Me thinks I'm doing something wrong and I need some guidance!