Microsoft Knowledge Base Article 310994 contains the following summary:
Microsoft Windows XP Setup boot disks are available only by
download from Microsoft. The Setup boot disks are available so that you can run
the Setup program on computers that cannot use a bootable CD-ROM.
If your computer does support booting from a CD-ROM, or if network-based installation is available, Microsoft recommends that you use those installations methods instead.
Future products will no longer support installation by using the Setup boot disks. Installation of future Microsoft operating systems will require the ability to start from the CD-ROM drive or by using PXE boot from the network. For more information about how to use PXE boot, visit the following Microsoft Web site: