Yes, there is a way to restore your GRUB.
Boot with your linux cd 1.
Type "linux rescue", then type "chroot /mnt/sysimage" and then "/sbin/grub-install /dev/hda". If it's not /dev/hda where Grub was installed, just change it, but usually this is it. And if you changed some partitions, edit and make changes in your "/boot/grub/grub.conf" file.