how to format xp???

get a bootable windows xp cd and go to your bios and set it to first boot on your cd, the just follow some instuctions...

Start backing up your files onto a CDROM. Make sure you have a good antivirus to install when you reinstall. You will need a full Windows XP disk (not the upgrade) so that you can boot to Windows XP Setup. 1. Insert your Windows CD. 2. Reboot the computer. It should either boot from the CD automatically or ask if you would like to boot from the CD. If it does not do either, you may need to change some boot settings in your BIOS. Consult your PC or motherboard's manufacturer if you need help with this step. 3. Windows Setup will begin. 4. When asked if you want to set up or repair, hit Enter to set up Windows. 5. Read the license agreement and hit F8 if you agree. 6. If the setup program detects an existing installation of Windows and asks if you want to repair it, hit Esc to skip the repair. 7. The setup program will ask you where to install Windows. Highlight the existing "C: Partition1" partition and hit D to delete it. Hit L to confirm. 8. Next, hit Enter to install Windows on the "Unpartitioned Space". 9. Format the space as NTFS and continue the installation. after you have installed windows and logged on the first thing you should do is install a good antivirus program like avg. after that put all of you backed up files back on the computer, and...... you have a fresh copy of windows installed

This site here will provide you detail instructions on how to format your computer for windows XP http://lifehacker.com/software/windows/geek-to-live--how-to-format-your-hard-drive-and-install-windows-xp-from-scratch-157578.php