Grub bootloader goes fail to boot in dual boot system after installing Ubuntu 12.10

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http://askubuntu.com – 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 (HowTos)