It's possible that a detected but unreadable hard disk drive could be accessed by using read-only software to copy files from the disk. If the drive appears in Disk Management and shows no signs of mechanical failure — such as clicking, grinding noises etc. — then you are in the territory where read-only software works. However, if the disk makes unusual noises, disappears on and off repeatedly or shows up for short periods of time before disappearing again, then you are not, and the difference matters more than any tool.
Reading data off a disk takes zero cost. Some actions can make the situation worse, and routinely do. These include formatting, running chkdsk, initialising the drive, and installing data recovery software directly onto the hard disk. Copying off, creating an image of your hard drive, and reading from the hard drive using read-only software cannot cause further harm to the hard disk.
This is one trial and it decides whether the following items are even worth trying.
Recovery software reads. But recovery software is unable to fix the physical parts of a drive, bring back a controller and find drives the operating system cannot see. Therefore the question is just whether the drive is showing itself to the operating system and working as long as it does.
Safe to attempt: The drive appears in Disk Management. It is always available. There's no noise coming from the drive. The issue is either a non-existent partition, a corrupt file system, deleted files, or the drive has been formatted. These are all problems related to logic errors on functioning hardware. Many can be resolved by using read-only tools.
Not safe: Any clicking, grinding, beeping. A drive that mounts then drops off. A drive which does not exist within Disk Management. In all of these cases scanning is hours of load on hardware that may not survive it. Drives routinely die partway through a scan intended to save them.
This is the most damaging thing done to externals and it is done with good intentions.
Most modern WD My Passport and My Book units encrypt their contents using hardware encryption whether or not anyone set a password. The encryption key lives on the small USB bridge board inside the enclosure—not on the hard drive itself.
If you take the drive out and connect it directly, which works fine on many other brands, you'll see a bunch of ciphertext. Windows will say it's an unformatted disk and offer to initialise it. Accepting that damages a drive that was healthy; and at that point, there is no way to recover anything from the disk without using the original bridge board.
If you've previously removed the WD housing off your drive: save both the housing and the board and send them in with the disk – do not throw them away. If you do, recovery of information becomes much more difficult and sometimes impossible.
Breaking any of these four guidelines could potentially convert a recoverable situation into a partially recoverable one.
The installation process writes and there is a chance that an installer writes into the unused portion of the disk containing your data. Try using a portable version from a USB stick if possible.
Don't write your recovered files back onto the drive you are recovering from. This will overwrite all of the remaining file areas that you haven’t recovered yet.
Any program that wants to fix/repair/rebuild your data drive writes. Anything scanning/carving is reading. Repairs do not read, they write.
A new noise in the drive, slow down in a scan, disconnects during the scan. All of these indicate that the hardware is deteriorating due to the added stress, and continuing will cost more than stopping.
Due to the drive needing to be readable for any tool to start.
The clicking, grinding or scraping sounds are due to the heads or motor. There is no way that a piece of software will be able to address mechanical issues like these. With each additional minute of scanning time you lose some of your surface area.
The disk drive is fine and the interface between it and the USB port is not. External drives are particularly prone to failed bridge boards. If the bridge board fails there is no conventional method for reading the data from the disk.
The disk drive spins but reports nothing; or it reports an unbelievable amount of capacity. Since the disk drive cannot describe its own characteristics, nothing else can read it in a normal manner.
WD units where the enclosure has been discarded. In all cases, the disk drive has been left intact, along with its contents, while the encryption keys were taken away with the board.
Is it listed in Disk Management? Is it staying connected? Is it free of strange noises? Then often yes – because read-only recovery software works well on missing partitions, unreadable file systems, and files you have deleted. If it is clicking or dropping off, no.
Not on a WD unit. Most modern WD My Passport and My Book units use hardware encryption, with the key on the USB bridge board. This causes a bare disk (not in its housing) to appear completely blank even when the disk is healthy, and will cause Windows to offer to initialise it.
The installer writes, and it may write right into the same empty area that contains the files you're trying to retrieve. It's best to install the software on a different drive from the one you are recovering, or to run a portable version from an external USB memory stick.
No. Always copy/recover your information to a third location. Write backs will overwrite the space still holding everything you have not retrieved yet.
No. Stop immediately. This is because the additional use of the failing hardware in any way continues to degrade its condition, potentially reducing the amount of recoverable data available from it later.
Mechanical noise; a failed bridge board; broken firmware or controllers; and WD drives that are encrypted via hardware and whose enclosure has been discarded. The four cases in common are drives which cannot be accessed normally. Therefore, there is nothing for software to do with them.