next, install modules of new kernel:
#make modules_install
then, generate a image for new kernel.
#cd /lib/modules #mkinitramfs -o initrd.img-2.6.30.4 2.6.30.4 #mv initrd.img-2.6.30.4 /boot
edit menu.lst file for grub booter, add following:
title Ubuntu 8.04.3 LTS, kernel 2.6.30.4 root (hd0,2) kernel /boot/vmlinuz root=UUID=98f69044-be12-4dde-95df-358dca35c632 ro quiet splash initrd /boot/initrd.img-2.6.30.4 quiet
