You need a floppy drive or a bootable memory stick.
After formating the floppy diskette or memory stick with the system files, you add an AUTOEXEC.BAT, CONFIG.SYS and CDROM drivers for the CD/DVD drive. I have the ones that
I created for Ghost on my XPS. With a little editing, they may work for you.
Nero will then see that the floppy or stick is installed. When you create it in Nero you will then select the
source of the bootable image (floppy or stick) that will be used when you burn the CD or DVD.