ubuntu 14.04 LTS won't boot [duplicate]

Question

just a few days ago i purchased a dell inspiron laptop with pre-installed ubuntu 14.04 LTS. i was installing the software center and updating in the software updater and it was just completed upto 85% and then it's just goes unresponsive . after this i tried to shutdown but it won't so i just forcefully shutdowned using the power button.when i restarted it's showing a black screen and it's showing the following-

            GNU GRUB version 2.02~beta2-9ubuntu1.3

Minimal BASH-like line editing is supported.for the first word,TAB lists possible completion. Anywhere else TAB lists possible device or file completion.

grub>_

please help me to step forward!

Answer 1

Find root partition

You must know what's your root partition to boot Ubuntu. Try:

ls

Now you can see some disks and partitions. You must list each partition to find where ubuntu is installed. For example:

ls (hd0,gpt3)

If this is your root partition, you can see the directories boot, dev, etc, usr,... When you find it:

set root=(hd0,gptX)

where gptX is your root partition.

Launching ubuntu

Find your kernel image with:

ls /boot

You can see one or more images with names like vmlinuz-3.13.0-29-generic. Now load the last image with:

linux /boot/vmlinuz-3.13.0-29-generic root=/dev/sda1

And

initrd /boot/initrd.img-3.13.0-29-generic

Now you can boot into ubuntu with

boot

Restore grub

Once in ubuntu, open terminal and write

sudo grub-install /dev/sda

Don't forget update before restart with :

sudo update-grub

Also, you can use a graphic repair tool like Boot Repair.

I hope this help you.