I had 12.04 with my dual boot system. Yesterday I downloaded Ubuntu 12.10 make bootable USB and choose Upgrade option in Installer. After installation Grub failed to boot my machine. I tried following to fix grub bootloder . Same problem I fixed with Ubuntu 12.04 using live USB but this solution not work for Ubuntu 12.10. Now coming at exactly where this solution goes fail.
I followed this steps after booting Live USB and opening terminal.
1) sudo fdisk -l to see where Linux is installed
2) sudo mount /dev/sda9 /mnt where sda9 is my linux partition
3) sudo mount /dev/sda9 /mnt/boot
4) sudo mount --bind /dev /mnt/dev
5) sudo chroot /mnt (No problems with this steps done perfectly)
6) grub-install /dev/sda when I type command I got error that
source_dir doesn't exist Please specify --target or --directory
How can I solve this ?