Why install XP? Why not take this as an opportunity to learn a new OS. I have never used (or heard of) Linux Forade -- is it Japanese?
-- but you might consider installing a "newbier" distro and learning off that first. Maybe the laptop had Linux installed on it for a reason (older hardware). If that's the case, why not install Debian.
However, if your set on using WinXP, just insert the Windoze install disc and delete the partitions currently on the laptop (Windwos will walk you through it; you use L I believe to delete existing partitions) and Windwos will install itself on the PC no problem. Hope this helps.