You might have been searching for instructions to reinstall grub after upgrading or reinstalling Windows on your systems to get your Ubuntu booting once again. Here are the steps.

1. Boot to the 9.10 Karmic LiveCD Desktop.


2. Open a terminal - Applications, Accessories, Terminal.


3. Determine your normal system partition – (the switch is a lowercase “L”) sudo fdisk -l
   
   
   
   • If you aren’t sure, run df -Th. Look for the correct disk size and ext3 or ext4 format.
   
   
   
   


4. Mount your normal system partition:
   
   
   
   • Substitute the correct partition: sda1, sdb5, etc.
   
   
   • GRUB 2 counts the first drive as “0″, but the first partition as “1″
   
   
   
   

   sudo mount /dev/sdXX /mnt



5. Only if you have a separate boot partition:
   
   
   
   • sdYY is the /boot partition designation (examply sdb3)
   
   
   • sudo mount /dev/sdYY /mnt/boot
   
   
   
   


6. Mount devices: sudo mount --bind /dev/ /mnt/dev


7. Chroot into your normal system device: sudo chroot /mnt


8. Reinstall GRUB 2:
   
   
   
   • Substitute the correct device – sda, sdb, etc. Do not specify a partition number.
   
   
   
   

   sudo grub-install /dev/sdX



9. Verify the install (use the correct device, for example sda. Do not specify a par