Just a thought
It is not easy to use a single hard drive with Windows XP and Linux.
However, check to see if you have any the following programs that came with
your Linux Distribution.
LILO (Linux Loader) or GRUB both are popular.
v-com.com or www.powerquest.com
If you are going to both OS on a single hard disk you can use the above to create your
partitions your will need more than 2. Linux can use 3 or 4 and Windows XP will need 1 all by itself.
You will need to determine how space Windows is using and plan for what it will need.
Windows XP will take a lot of space. It is easier to let the programs do most of the work.
I have a desktop with 2 drives each dedicate to a different OS I tried a single drive with Red Hat Linux and Windows XP.
In either case 1 or 2 drives you will need to decide on which system will boot up you can't toggle between the two.
Like I said it just a thought.