you cant 'upgrade' windows as such, you would have to format the computer and take win98 off, then you could put XP on.
if upgrading from win98 to xp than you can use xp cd from win98 desktop as xp cd will autorun. will give you the option to upgrade or fresh install of xp
Anytime that you update an OS, or reinstall an OS, reformatting the OS partition is the BEST way to do it.
to format your hd for win98, use the win98 bootdisk that you can make in the add/remove/bootdisk section in control panel
hi if you are have a winxp disc use that to format erase! then install yes format is best, nice and clean start to the world, like a new born baby!