|"When I use hard disk 1 with WinXP Pro, I get the flashing cursor "|
This means there is no master boot record on this drive.
This could also mean xp pro was installed with the xp home as master drive and due to this xp pro would not boot because its registry pointers say its on d: but when you move the drive to primary it is on c:
If you want to boot the xp pro disk as primary you have to do a repair install of xp. But then you would not be able to boot to it via the xp home boot menu, just keep that in mind.