If your hard disk is corrupted, crashed or damaged then it will not be possible to recover data from it using the normal read functions of Windows operating system. Windows will get stuck while reading the corrupted hard disk and your system would hang. But if you use DataRescue DD program, then it can read and save all possible data from undamaged sectors of the corrupted hard disk or memory cards.
DataRescue DD is called DrDD in short. It is a graphical disk image creation program intended for data recovery and backup of partially corrupted storage devices. It creates complete or partial images of disks or memory cards to files on another storage device. Having a disk image of the damaged disk allows you to perform multiple data recovery attempts on the raw data and reduces the chances of further corrupting the damaged disks.
You can download DataRescue’s DD from the DataRescue’s website. The download is a portable application inside a ZIP archive. You can extract the contents of the ZIP archive to a folder and run drdd.exe from there. For DrDD to work, you would need atleast two disks attached to your system – one source disk (damaged disk) and other destination disk (where image would be saved). You can select the source disk from the drop-down box. A destination iamge file is automatically selected but you can manually choose one too.
You do not have to change any other options, but you can specify the start and end positions of sectors to read from. DrDD would attempt to read only from this range of sectors. You can also set the size of data you want to read. Changing the sector range or data size automatically adjusts the other values. You can also set the read direction from start to end or from end to start. The direction change is important if you get locked while reading a damaged sector.
Finally, click on the Play button at the bottom to start reading the data from the disk. If DrDD encounters an unsuccessful read and drive locks up, it would switch the direction next time to read the data backward. This is a special technique of DrDD to read all the data while skipping the damaged sectors. The data read is automatically saved to the disk image file. You can use this file in any data recovery program to extract whatever data is left on the damaged disk. One of such data recovery programs is DataRecue’s own PhotoRescue.
You can download DataRescue DD from http://www.datarescue.com/.