How do I repair a Disk (is not booting)

Question

My hard drive will not boot. The screen comes up blank. It was working fine yesterday. No changes made. I am using Ubuntu 13.10 on 64-bit.
On the same computer, I am using an USB emergency installation to do this work. It booted just fine, all computer hardware also tested OK; hence, the problem is the Ubuntu installation.
This computer is ubuntu dedicated (no dual boot.)

Answer 1

Try use Boot-Repair for repair.

To add Boot-Repair to the repository use:

$ sudo add-apt-repository ppa:yannubuntu/boot-repair

To update your repository:

$ sudo apt-get update

To install boot-repair:

$ sudo apt-get install -y boot-repair

Once Installation completes, run boot-repair on terminal by typing the following command or select it by System → Administration → Boot Repair.

$ boot-repair