As mentioned. you can use P Magic to a) delete the 98SE entry in the Boot Magic boot manager and then format C Drive.
Or if not, you can go the Boot Ini file in C Drive and delete the same entry and then format C drive using your XP Disc as boot disc, or Windows 98 Boot Floppy disc.
All your systems files for XP should be on your D Drive.
Ep, glad to see you come back and tidy up...did want to ask a one day favor, I want to enhance my resume , was hoping you could make me administrator for a day, if so, take me right off since I won't be here to do anything, and don't know the slightest about the board, but it would be nice putting "served administrator osnn", if can do, THANKS