How do I read a damaged disk with dd for Windows?
Note that there are more methods to read a damaged disk.
Mac users, see the other dd article.

For Windows users, there is a good technique to create a disk image from the damaged disk or card, which is the first step towards recovery of footage.
Note that technique can also be useful to Mac users if the disk is not visible in the Finder, but is visible on a Windows PC.
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:
This program is free and distributed under GPL license. For more information, refer to the product page.
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 removeable 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 removeable 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.
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.
Note that you can monitor the size of the c:\usb.img file as it grows from 0 to the size of the disk: This will give you an idea of the progress.
How do I extract video from my .img file?
Now, if everything went fine, you should have a .img with a size similar to the disk capacity.
If the disk still contained video, the footage must now be inside your file as well.
Your .img file will now be split into tiles, like an archaeological excavation grid. We will search for video inside each tile.

You can reduce the number of tiles in the first pass, then narrow down once you have verified that your footage is present.
By trying every tile, you will map all the video present in damaged disk.