Help: format on XP Home?

Ok, so I tried again to reinstall stupid XP on this stupid Dell, lol, but I never get the option to FORMAT C first to get rid of the Dell crap and make a clean new install, anyone knows how to?
(installing from dvd drive straight from win cd with xp already installed, so the delete/format or whatever partition options don’t become available, and i don’t have a boot floppy…)

Urgent pls, want to get this done b4 new year :slight_smile: