During the upgrade from 12.04 to 12.10, grub-pc failed to update.
dpkg: error processing grub-pc (--configure): subprocess installed post-installation script returned error exit status 1 Errors were encountered while processing: grub-pc
I have already tried
apt-get purge grub-pc and reinstalling it, but the same error keeps coming up.
During the upgrade a few windows from Grub popped up asking me if I wanted to keep or replace the configuration files for Grub. I clicked the "keep" button on all of them. I suspect that might be the problem