The Windows XP CD is bootable.
Simply insert the CD into your CD-ROM drive, and restart your computer.
You may need to change the boot-order of your computer's devices so that it
chooses to boot to the CD-ROM before the hard drive. On newer computers,
you are often given the option to choose a boot order for a single boot. If
you don't see anything like that, you may need to modify a setting in the
BIOS. Please consult your owners manual, or call the PC manufacturer's tech
support line for assistance in doing so, as modifying certain BIOS settings
may have unforeseen consequences.
Once you're able to boot to the CD, you'll be given the option to
repartition and reformat your hard drive as part of the Windows XP setup
process.
Good luck!
--
Mike Kolitz MCSE 2000
MS-MVP - Windows Setup and Deployment
Remember to check Windows Update often,
and apply the patches marked as Critical!
http://windowsupdate.microsoft.com