Easiest way is to take your Windows XP Installation CD, and boot your
computer off of the CD.
You may have to go into your BIOS to tell your computer to boot off your
cdrom.
Once it starts booting off the cd, this will startup the Windows XP
installation process.
During the process, it'll ask you where you want to install your Windows and
options are given if you want to delete the partition and format the hard
drive.
Choose the format hard drive option and continue the setup and you'll have a
fresh brand new install of Windows XP.
Go inot your system Bios and set the cdrom to be the
Primary boot device, Save and exit, place XP cdrom in the
drive and just follow what is says to do. From that point
on it's pretty menu driven for you
