HD trouble

I just purchased a new computer, it came with a new Hard
drive with Xp home loaded on it. I put my old Hard drive in
(which was loaded with XP pro) and began transferring files
over. I noticed I could not access the "documents and
settings" folders, as they were all locked off from XP pro.
I was wondering if there was a way around this. I tried
booting using the old HD, but there was too much of a
hardware difference, and the computer just kept rebooting
itself.