Windows XP won't work with donor computer?

Out of boredem and curiosity, I attempted to install a hardrive from my really really old computer into my not-so-old backup computer. The newer computer, an HP Pavilion Slimline s5414y runs Windows 7. I took out the HD from my old HP Pavilion a1034n , which has Windows XP on it, and popped it into the Slimline. Both have SATA ports (rather than the older IDE), and everything went swimmingly. I changed the boot priority, and whenever I try to boot from the a1034n HD, my monitor turns black and says "out of range." To me, this would be a video settings issues, so I put both HD's back in their respective computers, and turned the resolution way down, then popped the a1034n back into the slimline. Still no dice. I did try other SATA ports on the MOBO, but they all bring up the "out of range" dialog on the montior. Anyone know the reason why this may be? I would guess that the Slimline's MOBO is not compatable with XP. Thanks for any input.

via Bleeping Computer Last 20 Posts http://www.bleepingcomputer.com/forums/t/511947/windows-xp-wont-work-with-donor-computer/