Quick one: How to re-install grub boot loader?

Hi, I've a quick one: Suppose you installed SuSE 8.1 on /dev/sdc2, then you duplicate the installation on another drive, say /dev/sdb1. I know to change /etc/fstab and /boot/grub/menu.lst, but the copy will not boot. Is there a need to reinstall the boot loader? With LILO, I know the procedure, GRUB is still new to me and I'm not sure how to do it. Any suggestions? -- Rafael