Most tools require you to have unpartitioned space to create a 2nd partition.
example.
If you installed xp n used the full Hard drive you cant trim it and make a 2nd partition if its all ready partitioned as one big C Drive.
if you install xp. delete the current partition (leaving you with X amount of unpartitioned space)
then manually create a partitin (example i dunno 40GB = 40000) this is when your booting up from XP CD.
In return leaves the rest of your hard drive unpartitioned. once xp is install.
Create the 2nd partition out of the unpartitioned space.
how to?
Right click my computer
manage
Disk management.
Thats all the info i can remember. All i know is its very difficult to repartition an already partitioned harddrive with out losing all the info