See "How to Remove the Windows XP Uninstallation Files"
(http://support.microsoft.com/?kbid=308008) if you upgraded Windows 98
to Windows XP. If you created a dual-boot system with Windows 98 and
Windows XP, remove Windows 98 from the BOOT.INI file and restart your
computer. Windows XP should start automatically. Now you can delete
the Windows 98 files from the HDD manually.
"How to Edit the BOOT.INI File in Windows XP"
(http://support.microsoft.com/?kbid=289022)