There is no "Fdisk" for XP.
The XP disk management tool performs all partitioning and formatting of
the file system.
You may choose to use third-party partition managers to accomplish this
task, with greater flexibility and power.
I suspect you have an OEM "Recovery CD", and not a retail MS XP CD for
installation.
Typically, such "Recovery" disk/s perform a disk wipe of the primary HD
before the installation, to return the system to its original state when
sold.
The initial set of apps and utilities supplied by the OEM are usually on
extra disks.
You MUST determine from your OEM if upgrading to XP SP1 requires using a
newer set of Recovery disks.
Clean Install Windows XP
http://michaelstevenstech.com/cleanxpinstall.html
[Courtesy of Michael Stevens, MS-MVP]
Upgrading to WINDOWS XP
HOME EDITION or PROFESSIONAL
Version 3.8 - Last Updated August 27, 2002
by Gary Woodruff, MS-MVP
© 2001-2002 by Author, All Rights Reserved
http://www.aumha.org/a/xpupgrad.htm
Windows Product Activation (WPA) on Windows XP
by Alex Nichol, MS-MVP
© 2001-2002 by Author, All Rights Reserved
http://www.aumha.org/a/wpa.htm