How to recover Ubuntu after installing Windows using Ubuntu live cd

1. Boot from Ubuntu live cd and open console

2. Be administrator

sudo -i

3. Find linux partition (/dev/sda7 4409 6435 16273408 83 Linux)

fdisk -l

4. Create a mount directory

mkdir /media/root

5. Mount linux partition to this directory

mount /dev/sda7 /media/root

6. Confirm that you can reach linux directories

ls /media/root

7. Install grub2

sudo grub-install --root-directory=/media/root /dev/sda

8. Reboot Ubuntu without live cd

9. Update grub to see other operating systems

sudo update-grub2

Alternatives

3. sudo gparted
9. update-grub