The simple way to install grub/ grub2 from any linux live-CD or any other bootable medium.
Step 1: boot from linux live CD
Step 2: mount your hdd
Step 3: chroot in the mounted filesystem
Step 3: install grub
Step 4: reboot
1 2 3 4 5 6 | mount /dev/sda1 /mnt/ mount -t proc none /mnt/proc mount -o bind /dev /mnt/dev chroot /mnt/ /bin/bash /usr/sbin/grub-install --recheck --no-floppy /dev/sda reboot |

