I've been using PM for years, and have had generally very good luck with it,
with very few exceptions. The vast majority of the time it performs its
duties admirably. One piece of advice, if you're going to be creating new
partitions on a drive which already stores files: make sure to defrag the
drive first in order to consolidate all the data, then partition away. Oh,
and (as always) make sure you have a backup.
The only place I know of that XP has a built-in partitioning utility is in
setup; if you partition from there you're well on your way to reinstalling
XP in one fashion or another. That method is not recommended if you want to
conserve your data.
--LB