Boot from your installation CD (Windows XP).
Follow the directions to install.
When you get to the part where it wants you to choose the partition you wish
to install on, DELETE the partitions.
Create new one(s) and install Windows XP.
See the link in my signature for more options as it is rarely necessary to
completely start over with XP.
You boot from the CD and do a clean install.
Click on or copy and paste the link below into your web browser address bar.
How to clean install XP. http://michaelstevenstech.com/cleanxpinstall.html