How to fix or Rebuild the MBR and recover lost partitions on a Hard Disk.

There are many different ways to do so. But in this tutorial, I've picked the quickest, easiest and safest way to do it =). You will only need other advanced ways and manual editing of the MBR partition table in extreme cases (I bet you won't need a tutorial if ur one of these ppl 'eh). We will use the ubuntu live CD/DVD in order to fix this problem. It will fix issues on all File systems (Linux, Windows and Mac) including the famous ext4 and FAT32, NTFS Partition types so you can boot into your Operating System normally again with the data intact, sound and safe on the hard disk =D

A little literature =)

MBR known as Master Boot Record is a certain partition (Sector to be more precise) of the Hard disk that contain vital data about the hard disk such as partition maps/tables, Boot flags required to boot up and so forth. you can lose partitions or your MBR can get damaged for various reasons such as sudden shut down of the computer or maybe due to a Virus. your MBR might get also corrupted if you failed to install multiple Operating Systems aside in dual-boot configuration or accidentally change the file system of the harddisk using a forced quick format. For example changing an NTFS partition to ext4 or vice versa. Same for changing the file-system type of the entire hard disk (XFS, HFS, MBR, DFS, ...). 

You might actually go like "Oh Noez, Now all the data is gone!". Well actually not =D even if u did a quick format. cuz quick format doesn't actually remove the data from the hard drive physically. So you can actually retrieve the data and restore the disk the way it was if you mess with the MBR Flags and play with the partition maps (Assuming that you know the correct data architecture on disk). Good for you, there have been some utilities that are smart enough to scan the disk and guess the correct architecture and stuff ;)

Symptoms of corrupt MBR and/or lost partitions.

-  You lose all your partitions or a significant number of them that you can't find using any disk utility.

-  Your computer won't boot at all and The Operating System's bootable CD fails to recover.

-  Your hard disk give you weird info about their free space such as negative values.

-  You receive an error when opening a certain partition or receive a BSOD then ur computers restarts.

How to?

1. Insert Ubuntu Live CD/USB and boot from it.

2. Click Try Ubuntu as in the Screenshot below. (This would make you run ubuntu live from the CD/USB)

3. Make Sure you have the Ubuntu "Universe" and "Multiverse" repositories enabled and that you are indeed connected to the internet!

4. Type in the following commands:

 sudo apt-get update
 sudo apt-get install testdisk
 sudo testdisk 

5. After that, you'll see something similar to the screenshot below. Press Enter.

6. Select a Hard disk and press enter, then select you hard disk type and press Enter. Most commonly if ur using windows or linux it will be the first choice. (NOTE: ONLY SELECT NONE ONLY IF YOU KNOW WHAT YOU ARE DOING)

7. You end up with various choices like the screenshot below, press Enter.

8. Hit Enter again to Analyse the disk for recoverable partitions and try to fix MBR.

9. At the end it will list all potential possible partitions and prompts you to fix the MBR =D. Reboot and everything should be fine and back to normal. (In the worst case your OS's Bootable CD will be able to recover by just rewriting the boot code again into the MBR)


Finally, If you faced any problem with this tutorial please lemme know by posting a comment below and I would be glad to help. You can also Contact me if you really want the dirty other geeky methods I Was talkin abt ;)