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It have been a week since I use Ubuntu alongside with Windows 8. Yesterday I tried to reinstall Ubuntu 12.04 from the CD, I chose the option Erase Ubuntu 12.04.4 LTS and reintall, I followed the installation process as I followed when I installed it for the first time.

When the pc restarts, after reinstallation, I had a Grub problem so I followed the steps from this webpage , I restored the Grub.

The problem came when I try to enter in Ubuntu from the grub, I got a black screen and the message is :

Kernel panic - not syncing : VFS : Unable to mount the root fs on unknown-bloking(0,0)
CPU: 2 PID : 1 Comm: swapper/0Not tainted 3.11.0-15 generic #25 pe1-Ubuntu
Hardware name: Dell Inc. Inspiron 5423/0H4MCJ. BIOS A0206/21/201
0000000000008001 ffff8802238addc8 ffffffff8173bc5e 0000000000001
ffffffff81ae6718 ffff8802238ade48 ffffffff8172e8d8 ffff8802236ea
ffffffff00000010 ffff8802238ade58 ffff8802238addf8 0000000000017
Call Trace:
[<ffffffff8173bc5e>] dump_stack+0x46/0x58
[<ffffffff8172e8d8>] panic+0c1/0x1d7
[<ffffffff81d263ec>] mount_block_root+0x17/0x231
[<ffffffff81d26624>] mount_root+0x53/0x57
[<ffffffff81d26795>] prepare_namespace+0x16d/0x1a6
[<ffffffff81d2610d>] kernel_int_freeable+0x124/0x131
[<ffffffff81723be0>] ? rest_int+0x80/0x80
[<ffffffff81723bee>] kernel_int+0xe/0xf0
[<ffffffff817508ec>] ret_from_fork+0x7c/0xb0
[<ffffffff81723be0>] ? rest_int+0x80/0x80

In this moment I can use Windows 8 normally, I access from the grub.

Thanks in advance for any help you are able to provide.

share|improve this question

Download Boot Repair iso image, burn it on a regular CD, reboot computer with your new Boot Repair CD in tray, and choose the 'Recommended Repair' option after Boot Repair finished loading. You should be able to boot into Ubuntu after that.

If you can boot into Ubuntu, first thing to do, after you login is to run a required update-grub command. Code:

sudo update-grub

And I think that you're done. Very important is to choose the right Boot Repair iso image

If you're running Win8 and Ubuntu 64bit, then you choose the 64bit iso image for Boot Repair,
If you're not then you choose the 32bit iso image, and download it and burn it. Boot Repair iso image can also be written on any decent USB pendrive (with a minimum 1GB space) using Unetbootin tool.

share|improve this answer
First of all thank you for this clear response. I would like to know if I use this program it could damage my Windows 8 partion? I really want to not mess up Windows 8. – user256446 Mar 16 '14 at 11:45
Since you are using grub to load Win8 system, using Boot Repair cd should not create any problems. Nevertheless, as a precaution, you can visit the following webpage to learn more about Win8 and dual boot issues with Ubuntu:… Pay attention to 'Solution 3: Boot to Linux and Use efibootmgr' which can be used to restore your WIn8 boot, and also allow you to load Ubuntu in dual boot. – Taz D. Mar 16 '14 at 13:12

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