When a hard drive goes bad, its sectors can become corrupt, data can go missing, or the drive may no longer boot at all. Once a hard drive fails and cannot be accessed normally by a computer, accessing the hard drive using special software may help recover some of the data from the bad drive so that you can back it up. Sometimes, the hard drive is so damaged that only data recovery professionals can retrieve it, and in many cases, not all of the data can be recovered.
Determine the type of connection used by the hard drive. An external hard drive will often connect by USB, while an internal hard drive may need to be installed into the computer or connected using a special adapter.
Shut the computer down if it is turned on and unplug it completely, including all hardware plugged into the computer. Open the case hatch that gives you access to the internal components of the computer, usually secured by a screw or latch on the side of the computer case. Unscrew the screws securing the hard drive in place in the computer case and remove it from the case.
Connect the internal drive to a bootable computer using an external USB hard drive adapter. Common types of hard drives include SATA and PATA. (Most newer hard drives are SATA.) Connect the internal hard drive to the appropriate USB adapter, PATA or SATA, so you can plug it into an available USB port on a working computer.
Download or purchase a professional-level data recovery software program. Advanced data recovery programs offer more functionality than freeware recovery programs, and may work to retrieve data when a free program does not.
Install the data recovery program on the computer to which the corrupted hard drive is attached. Run the downloaded file or insert the data disk into your computer and access the installation file. Complete the program by following the instructions given to you by the recovery program.
Run the data recovery program. If available, choose the advanced option or look for a selection that allows you to recover data from corrupted drives.
Select the corrupted hard drive and run the data recovery program. Specify a folder in for the recovered data and remember its location. Allow the data recovery process to complete. Depending on the size of the drive, this may take up to a full day.
Connect the backup hard drive to the computer and copy the recovered data from the designated folder to the hard drive in order to back it up. Open the folder on the backup hard drive and ensure that all of the desired data has been copied into the folder.
Professional data recovery software program
PATA- or SATA-to-USB hard drive adapter (optional)
Working computer (optional)
Additional hard drive
Removing the corrupted hard drive is only necessary if the computer will not boot to run the recovery program.
Ensure that the recovery program you choose will access corrupted drives; some programs only recover deleted files and do not work on corrupted drives.
If one program does not recover the desired data, you may see results with another program, but it may be faster to turn the broken hard drive over to a data recovery professional.
Always shut down and unplug any computer before opening the case, and before removing, installing or touching any of the hardware inside.
Research freeware data recovery programs carefully to make sure they will not cause more damage to your hard drive during use.
Do not shut your computer off in the middle of the data recovery process or you may permanently damage the drive.