Restore boot manager after installing windows 7 over linux



  • Boot from the ubuntu Live CD.
  • Open the terminal from applications -> Accessories -> Terminal.
  • Then find the partition of your Ubuntu OS from the list generated with the command,
    • sudo fdisk -l
  •  If your ubuntu(linux) partion is sda6,
    • sudo mkdir /media/sda6
    • sudo mount /dev/sda6 /media/sda6
  • After that you have to reinstall the GRUB
    • sudo grub-install --root-directory=/media/sda5 /dev/sda
  • If everything went alright you should be able to reach the GRUB boot menu when you restart the computer. You can find more information from here.