The problem is almost certainly that grub-pc is misconfigured on your system. Get back in using a live CD (https://help.ubuntu.com/community/Grub2#METHOD%203%20-%20CHROOT), but instead of running grub-install, run 'debconf-show grub-pc' and post the output to this bug. Then run 'dpkg-reconfigure grub-pc' and make sure that all of the disks on your system are selected but none of the partitions, unless you know better. Then exit, unmount, and reboot as documented on the help.ubuntu.com page.
The problem is almost certainly that grub-pc is misconfigured on your system. Get back in using a live CD (https:/ /help.ubuntu. com/community/ Grub2#METHOD% 203%20- %20CHROOT), but instead of running grub-install, run 'debconf-show grub-pc' and post the output to this bug. Then run 'dpkg-reconfigure grub-pc' and make sure that all of the disks on your system are selected but none of the partitions, unless you know better. Then exit, unmount, and reboot as documented on the help.ubuntu.com page.