Reformatting Win XP Pro

I have an IBM Think Pad which was previously networked, I am having problems getting it to boot to the floppy, so I can boot to Win 98 & do an Fdisk. Any suggestions?
It keeps wanting to boot to Win XP where it wants the login/password. It is no longer active. My boss gave me the laptop & said it was mine, reformatting it is my problem! 🙂