I compiled new kernel on my system and booted successfully from it

I want to know regarding the process of fresh installations when you boot from a CD or DVD or from your hard disk or Lan for installing a fresh copy of linux on your machine every vendor specifies kernel image and initrd in boot directory on installation DVD or First CD inside /boot/loader directory

Fedora: vmlinuz and initrd.img
Suse: linux and initrd
Mandriva: vmlinuz and all.rdz
Ubuntu: vmlinuz and initrd.gz
Gentoo: gentoo and gentoo.igz
Knoppix: vmlinuz and initrd.img
Slackware: bzImage and initrd.img
Debian: vmlinuz and initrd.gz

What I am not able to understand is how to make the bzimage and initrd of newly compiled kernel which are in arch/i386/boot/bzImage
to be capable of booting for fresh installation that starts with a new installation procedure rather than being able to boot with new kernel with a few rpms that I already have from the ISO of my old distribution

which are released when a new flavour of some linux distribution comes with a new kernel