A failing hard drive should not be taken lightly. Maybe you are noticing that you can't load some of the files on the drive anymore or that write processes sometimes fail, or you received a notification by a disk monitoring tool that the drive will likely cause these issues in the near future.
While you can go ahead and try and copy all the data that is stored on the device to another, you sometimes may run into issues doing so especially if part of the drive is already corrupt or non-readable.
Data recovery software may aid you in the recovery of the files in this case, and while you can run a program like Recuva, Free Recover or Unstoppable Copier to see if those files can be recovered, it is usually better to create an image of the disk first to run the recovery software on the image and not the original drive.
DataRescue DD is a free program for Windows and Mac operating systems that can create an image of a hard drive connected to the system. It can not create an image of the system drive though, only secondary hard drives seem to be supported by it.
The program itself is relatively easy to use. Vista and newer Windows users need to run the program with elevated rights so that the drive list can be populated. If you run the software without the required rights, you will notice that no drives are identified by it.
Select the drive under source that you want to create an image of. You should also make sure that you pick a destination that has sufficient free space to hold the data. One interesting option is the ability to create a partial image instead of a full image. You can specify the size in Megabyte as well as the start and end points for that, or the same for sectors of the drive. A click on the play icon starts the image creation and a file with the .dd extension will be saved to the local drive in the process. This is a raw file that most recovery programs should have no troubles to read and process.
The program supports two read directions and it may make sense to create images using both directions to avoid situations where a drive image cannot be completed because of corrupt sectors.
DataRescue DD is not the only program that enables you to create a disk image of a hard drive. Several tools that we have reviewed in our data backup overview for Windows can do that including DriveImage XML. Still, if you are looking for an easy to use program to create a disk image for recovery purposes, you may find this one suitable for the task as long as you need to create an image of a non-system partition or drive.