Need to format

But my floppy drive doesnt show up as one of the options for my boot sequence setup from the bios. The floppy is recognized by XP. I can see it and write to it from the “My Computer” window. But when I go to set the boot sequence so I can run my 98 boot disk. The option isnt there. Any clue? What can I do at this point. I need to format this computer so I can install Advanced server on it. WHen I try to run the cd (advanced server). It says I cant overwrite XP with a older OS.