Repair partition table and boot sector

This can take many hours, even days, to run on large hard drives bigger than 500GB
When I first wrote this guide, 1TB drives were very rare. Now they are quite common. Be aware that this can take a very long time to run. You can do other stuff on your computer while it runs as long as it is not something that tries to use the bad drive.

If there is physical damage, then consider sending the drive to a professional recovery service since physical damage often continues to degrade the data and simply powering on the drive may make data become irretrievable.

If there is no indication of physical damage then you can continue. In order to repair the most common problems that cause an external disk to suddenly become RAW we will use TestDisk.

Download Testdisk
http://www.cgsecurity.org/testdisk-7.0-WIP.win.zip
and run testdisk_win.exe

TestDisk is a console application so you have to use your keyboard to interact with it instead of your mouse.

Choose CREATEand hit enter

 

Make sure that your external disk is highlighted
Choose Proceedand hit enter

 

Select Intel and hit enter (there is a slight chance that the partition is EFI GPT if the drive is 2TB or greater in size and at the bottom of this screen it says that Hint: EFI GPT was detected. If that is the case, select EFI GPT instead and try that.)

 

Select Analyseand hit enter

 

The partition data looks incorrect (an explanation of why is beyond the scope of this article)
Select Quick Searchand hit enter

 

Say ‘Y‘ if it asks if the disk was made in Vista/Win7 (even if it was made in XP say ‘yes’)

 

Now the Quick Search will run

 

When the Quick Search completes, we see one partition (if you only see the option to CONTINUE at the bottom of the screen press ENTER one time to continue to the screen that you need to be at).

 

Lets look at the data on that partition press
P
and you should see a list of files/folders in the partition.

 

Hmmm… This looks like a bunch of diagnostic tools but not our missing data. We’ll need to look further. Press
Q
to go back a screen and then press
enter

IF YOU SEE ALL YOUR FILES THEN SKIP THE DEEPER SEARCH AND GO TO THE STEP DESCRIBING SELECTING WRITE

To get to this screen, select DEEPER SEARCH and press enter.

 

Naturally, the Deeper Search takes longer than the Quick Search

 

When the Deeper Search completes we now see two partitions. The one we saw after the quick search and another one.

 

Select the new partition and press
P
to see the files/folders and now we see the data we want to make visible again.

 

Press
Q
to go back a screen and then press enter to get to this screen.
Select WRITE and press enter in order to write our new partition table to the drive.
DO NOT WRITE A NEW PARTITION TABLE IF YOU DID NOT SEE YOUR FILES/FOLDERS That means the proper partition table was not found and you will have to try a different technique to recover your data.

 

Press Yto confirm that you want to write the new partition table.

 

As I mentioned at the start of this repair, this disk also has corruption in the boot sector of the partition that we are trying to make visible again. When this is the case TestDisk will stop at this point and ask you to fix it before it finishes writing the new partition table. If the backup boot sector is good (as in this case) simply choose BACKUP BSand press enter. In the event that the backup boot sector is also bad then choose REBUILD BS.

 

Press Y to confirm the boot sector repair

 

Then choose QUITand press enter

 

Regardless of whether a boot sector repair is required or not, you will end up at this screen where all you can do is press enter. Then hit Quntil you are out of TestDisk.

 

Now reboot the computer to see if the drive is now visible.

Here are the results for the drive used in this example…

 

 

Copyright © 2012, Balk ICT - Uw computerhulp
Computerhulp IJsselstein, Computerhulp Nieuwegein, Computerhulp Utrecht, Computerhulp Benschop, Computerhulp Lopik,Computerhulp Houten,Computerhulp De Meern,Computerhulp Culemborg,Computerhulp Driebergen.