More commonly known (universal) method to restore the bootloader as described in article RESTORE GRUB BOOT LOADER IN LINUX MINT AFTER INSTALLATION/REINSTALLATION WINDOWS
But consider another way...
In Grub Rescue Mode is available only four commands:
ls set unset insmod
And as we know, Grub consists of two parts:
- The first part of GRUB recorded in the MBR of the disk. It contains the basic functionality and no more. This is exactly these 4 commands.
- The second part GRUB - she lies in the directory /boot/grub and contains modules to boot the system.
Therefore we can restore GRUB is as follows:
- we need to load all the modules to enable all the functionality of Grub
- to start with the desired section
For the beginning by command ls look what devices we have available in GRUB2.
Now, the enumeration of sections, we need to find the drive with the installed Linux Mint. In the figure, the correct disk number 6
I want to note that Grub sees only the disk partitions and does not understand what kind of file systems are on them. Therefore, all sections, we are seen as msdos.
I guessed section, and if you will not know what's where, have to try few times. Maybe things will become more complicated if you have more than one HDD, then you will see hd0, hd1, etc.
When the desired partition is found, you need to specify the path to the modules Grub2:
And the path to the file system kernel image:
Check the proper ways
After connecting the module with the command normal, Grub will go into full operations. Look at the screenshot above.
It will automatically find all operating systems, and displays the boot menu. Look at the screenshot below.
To secure the changes you must boot to Linux Mint and execute the following commands in terminal:
sudo update-grub sudo grub-install /dev/sda
sda - our drive with the installed system
These commands will reinstall the code in the MBR Grub, and it will automatically pick up the second part of the partition from which you booted.