How to format C

I have win xp home and have decided for various reasons to format my H/D and load everything again. I can’t remember the procedure having only formatted C once before.

The only boot disk (floppy) I have is a win ME one ( I couldn’t find a create start-up disk option in XP?). I know I need to boot into DOS but don’t know how to get there – I tried setting BIOS to boot from the ME start-up floppy and also the win XP CD but so far I’m lost!