I use two operating system in a single pc. One is WINDOWS and another one is UBUNTU (Linux). I was using windows and partitioned a drive and restart. Suddenly my GRUB ( boot menu ) just vanished and showing the message “ unknown filesystem, grub rescue ”. My fellow colleague Tanzim helped me a lot to resolve the situation to recovery the system. We reinstalled the GRUB and it worked fine. Every file and folder, filesystem were intact. What I lost, the windows selection menu in boot menu. We searched the INTERNET and found a way to load the windows selection menu again in the boot menu. Let me show the way to do it.
First Reinstall the GRUB.
For this you need a UBUNTU live cd or UBUNTU image on a pendrive.
a. insert the cd or pendirive, restart the pc and select the boot device as pedrive/cd
For Ubuntu grub rescue follow these steps:
1.Boot from the Ubuntu Desktop live CD.
2.In Live Desktop session open terminal.
3. In Terminal tpye sudo fdisk -l
It will display all partiton of the disk.
The partation which have Linux under System column is your drive in which ubuntu linux is installed. In screenshot ubuntu partition drive is /dev/sda11.
4. Mount the ubuntu partition drive
sudo mount /dev/sdXX /mnt(example ‘sudo mount /dev/sda11 /mnt’ ,don’t miss the spaces.)
5.Only if you have a separate boot partition:
sudo mount /dev/sdYY /mnt/boot.
6. Mount the virtual filesystems:
sudo mount –bind /dev /mnt/dev
sudo mount –bind /proc /mnt/proc
sudo mount –bind /sys /mnt/sys
7. To ensure that only the grub utilities from the LiveCD get executed, mount /usr
sudo mount –bind /usr/ /mnt/usr
sudo chroot /mnt
8. If there is no /boot/grub/grub.cfg or it’s not correct, create one using
9.Now reinstall Grub
grub-install /dev/sdX(eg. grub-install/dev/sdaDo not specify the partition number.
10. Verify the install
sudo grub-install –recheck /dev/sdX
11. Exit chroot : CTRL-D on keyboard.
12. Unmount virtual filesystems:
sudo umount /mnt/dev
sudo umount /mnt/proc
sudo umount /mnt/sys
If you mounted a separate /boot partition:
sudo umount /mnt/boot
13. Unmount the LiveCD’s /usr directory:
sudo umount /mnt/usr
14. Unmount last device:
sudo umount /mnt
This should reinstall your grab, but you might not see the windows menu right now
what your need to do is as following
from your terminal
1. sudo apt-get install os-prober
2. sudo update-grub
Hope it will restore your windows name in boot menu.