I want to delete everything on the hard drive of my laptop and reinstall XP Home (a legal OEM copy). How on earth do I do this? I can't even get into Windows (hence part of the reason for reinstallation) so I can't do it there. Booting from the CD only gives me the option to repair XP, which does absolutely nothing except add another to the welcome screen.
Help

What do I do? I bought the XP disc especially for this reinstallation, but my laptop (a Dell one, btw, and far too old to be eligible for any kind of warranty support) really doesn't like it...