Reinstalling Windows XP

i need to reinstall xp sp2 to a laptop but i need to do it through usb i dont know how can someone tell me pls
Answer #1
See if this link work for you.
http://skarh.wordpress.com/2008/11/20/install-windows-xp-through-usb/
Answer #2
i dont understand it in the end what does he write
Answer #3
http://komku.blogspot.com/2008/11/install-windows-xp-using-usb-flash-disk.html
http://www.daemonnews.org/2010/10/23/install-windows-xp-sp3-x86-from-usb-drive-pen.html