Can not access Hard Disk from Ubuntu 12.04 live CD

Question

I am new to Ubuntu. I have installed Ubuntu 10.04 . OS is corrupted in my system and can not boot. I just go through recovery mode and upgrade my OS but still i can not boot. Using Ubuntu 12.04 Live CD, the system is boot and log in. I can not access my hard drive.

In Disk Utility, it shows like this :

Write cache :  Enabled                     Connection : ATA
Partitioning : Master Boot Record          Device : /dev/sda

In Disk Usage Analyzer, it shows like

Totalfilesystemcapacity 100%   483.2 GB
Totalfilesystem usage   21.6%  104.3 GB

Refer to this post Can't mount hard drive. Ubuntu 12.04,

I have use command

sudo fdisk -l (shows as  Disk /dev/sda : 500.1GB ..)
sudo mkdir /media/newhd (worked)
sudo mount /dev/sda /media/newhd 

In media/newhd folder, some unreadable files are loaded. They are

bin, boot, cdrom, dev, etc, home, lib, media, mnt, lost+found, opt, proc, root, run, sbin, selinux, srv, sys, tmp, usr, var, initrd.img, initrd.img.old, vmlinuz, vmlinuz.old

Please provide me a solution to retrieve my files.

Answer 1

If you can only boot through a live CD, i would suppose that you grub is corrupted.
Your live CD should have the program "G-parted" installed on it, which should show you your partitions correctly, if you want to change partitions or anything by the like.
Now for the booting problem:
To get grub back to work, you can do it easily by using boot-repair.
The following commands will add the repository for it, update you repository's (very important, do not skip) and install the program.
sudo add-apt-repository ppa:yannubuntu/boot-repair
sudo apt-get update
sudo apt-get install -y boot-repair && boot-repair

further instructions on how to use the program here:
https://help.ubuntu.com/community/Boot-Repair

After that, you should be able to use ubuntu normal again and access your files