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Osama Ahmaro
Asked: 2016-10-05 04:30:59 +0800 CST

How do I repair/restore grub2?

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I currently have a Windows 10 and Ubuntu 16.04 dual boot on my PC. This issue happened because i have installed windows after Ubuntu.

I have tried to boot from a live-USB and reinstalling Grub using the terminal following this link http://howtoubuntu.org/how-to-repair-restore-reinstall-grub-2-with-a-ubuntu-live-cd

Also using the grub repair tool but with no success!

And now I am stuck in this grub2 command line screen:

Minimal BASH-like line editing is supported. For the first word, TAB lists possible command completions. Anywhere else TAB lists possible device or file completions.
grub>

I got this output after running lsblk; sudo parted -l 

Model: ATA WDC WD3000HLFS-0 (scsi)
Disk /dev/sda: 300GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 

Number  Start   End    Size   Type     File system  Flags
 1      1049kB  525MB  524MB  primary  ntfs         boot
 2      525MB   300GB  300GB  primary  ntfs

Model: ATA WDC WD3000HLFS-0 (scsi)
Disk /dev/sdb: 300GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 

Number  Start   End    Size   Type     File system  Flags
 1      1049kB  300GB  300GB  primary  ext4

Model: ATA Samsung SSD 840 (scsi)
Disk /dev/sdc: 500GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 

Number  Start   End     Size    Type      File system     Flags
 1      1049kB  8002MB  8001MB  primary   linux-swap(v1)
 2      8003MB  500GB   492GB   extended
 5      8003MB  28.0GB  20.0GB  logical   ext4
 6      28.0GB  28.5GB  500MB   logical   ext4
 7      28.5GB  43.5GB  15.0GB  logical   ext4
 8      43.5GB  58.5GB  15.0GB  logical   ext4
 9      58.5GB  88.5GB  30.0GB  logical   ext4            boot
10      88.5GB  500GB   412GB   logical   ext4

Model: JetFlash Transcend 16GB (scsi)
Disk /dev/sdd: 15.8GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 

Number  Start   End     Size    Type     File system  Flags
 1      1049kB  15.8GB  15.8GB  primary  fat32        boot, lba
boot

1 Answers

  1. Best Answer

    From your Question and comments the resolution will be the following:

    Boot to the live disk and run these steps. the /dev/sdXY is replaced for the specifics of the information you have provided.

    The c6 in step 1 and the a in step 4 are variables. The c6 should be replaced with the partition of your Ubuntu install. The a should be replaced with the default boot that you have set in your bios.

    The prefix :$ and :# are the command prompts you see on the terminal.

    1:$ sudo mount /dev/sdc6 /mnt
2:$ for i in /sys /proc /run /dev; do sudo mount --bind "$i" "/mnt/$i"; done
3:$ sudo chroot /mnt
4:# grub-install /dev/sda
5:# update-grub
6:# exit
7:$ for i in /sys /proc /run /dev; do sudo umount "/mnt/$i"; done
8:$ exit

    Reboot.

    Ensure that you have UEFI enabled in your BIOS if is a later model computer with that feature.

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