Whenever an SD Card with precious video moments is being formatted by mistake, a cold sweat runs down the back of the culprit. Here we will show you how to bring back those deleted files through three posts with detailed steps. We will Undelete Raw Footage, then we’ll Find Deleted Videos and finally Fix Deleted Videos.

Hint: We use our MP4repair.org video repair tool during the process…

In Windows there is a good technique to create a disk image from the damaged disk or card (even if it was formatted), which is the first step towards recovery of footage. For Mac users there are some other ways to get back those videos using Aero Quartet services.

In a nutshell, we use a small utility called dd for Windows that is able to read the raw data of a disk. (From now on, we will just use the generic word “disk”, and it can refer to a hard disk, a memory card or a USB drive).

Under the premise that the disk is readable, i.e. Windows detects it when you plug the disk or insert the card in the reader, dd for Windows should be able to create a file with about the size of the disk.

Here is the process, step by step:

1. Download dd utility: http://www.chrysocome.net/downloads/dd-0.5.zip
This program is free and distributed under GPL license. For more information, refer to the product page.

2. Unzip it and make a copy on your Desktop.

3. Connect the damaged disk to the computer.
Your PC must detect it, otherwise dd won’t work.

4. Open a DOS shell (i.e. launch the program called cmd) and type the command: 

dd --list

And you will get a list of the devices connected to your computer.
Here is what we get for example:

rawwrite dd for windows version 0.5.
Written by John Newbigin
This program is covered by the GPL. See copying.txt for details
Win32 Available Volume Information
\\.\Volume{aef46cf9-3e3d-11de-b8c6-806d6172696f}\
link to \\?\Device\HarddiskVolume3
fixed media
Mounted on \\.\c:

\\.\Volume{aef46cf8-3e3d-11de-b8c6-806d6172696f}\
link to \\?\Device\CdRom0
CD-ROM
Mounted on \\.\d:

\\.\Volume{6f41f4b2-d11a-11de-b318-001d4f88486c}\
link to \\?\Device\Harddisk1\DP(1)0-0+5
removable media
Mounted on \\.\f:

Don’t be afraid, it’s just a list of the devices connected to your computer.

Here the interesting device is the F:\ volume described as removable media: this is the card that we want to recover. Take note of the corresponding volume name:

\\.\Volume{6f41f4b2-d11a-11de-b318-001d4f88486c}

This volume name starting with \\.\Volume{ and ending with } will be used in step #6.

5. Verify that you have enough space available on your hard disk.
The rule of the thumb is that a 4GB card will produce a 4GB file, a 120GB hard disk will need 120GB, and so on.

6. Type the command below to read your disk.
Of course, you will replace this volume name by the volume name that you have noted in step 4:

dd if=\\.\Volume{6f41f4b2-d11a-11de-b318-001d4f88486c} of=c:\usb.img bs=1M --progress

This command creates a file called c:\usb.img that is a carbon-copy of the damaged disk.

It can take a long time. For 1GB, it can take one minute or more. For 120GB, it will take several hours. Progress of the file creation will be shown on the screen from 0 to the size of the disk.

After following this process, you will have an image file of your damaged card but still no access to the footage. We’ll see how to access and repair it in the second post of this series: Find Deleted Videos on an SD Card.