boot error

I’m having this problem, after the installation of suse 10.2 it does not boot, i don’t know why, it looks like it can’t find the boot area. I’ve tried reinstalling the boot but it said “Error installing GRUB” error 21: selected disk does not exist. I don’t know what to do, please help!!

use yur install dvd to repair the grub
read here: GRUB Boot Multiboot openSUSE Windows (2000, XP, Vista) using the Grub bootloader.