to recover grub

1. open the live version
2. open the terminal and run sudo fdisk -l to see where Linux is installed
3. run sudo mount /dev/sdaX /mnt where x is the number you have found Linux word in
4. run sudo grub-install --root-directory=/mnt /dev/sda to install grub
5. run sudo update-grub to update grub
6. reboot
Good حظ