A drive that does not show up within File Explorer, Disk Management or Finder could represent everything from a loose cable connection to a failing drive. Here's how to determine if you have a bad connection or a failing drive, and some tips for preventing potentially irreparable problems during the recovery process.
Say no when Windows asks if you want to format or initialise the drive. The file system is probably damaged, but the data isn't lost, and initialising can overwrite it.
Before you even attempt to access your files, see if the drive shows up in BIOS/UEFI. This may be the best way to determine what went wrong. In general, if the drive appears in BIOS but not File Explorer or Finder in Windows/Mac, then the problem is logical and the drive is good. There could be issues such as a missing drive letter, a RAW partition, a missing driver, etc. On the other hand, if the drive does not appear in BIOS, there is probably something bad going on within the drive (board, motor, heads, SSD controller). Knowing whether the drive is dead makes a huge difference in how you proceed.
There are several steps that you can take with no risk (none of which will affect the hard drive) before you assume that something has gone terribly wrong.
One of the most common reasons for a hard drive not being seen by your computer is either an improperly connected or defective cable. Try using another cable; if you have a desktop computer, try using the ports located at the rear of your motherboard instead of those found on your front panel.
If the drive shows up somewhere else (even if it's just a different machine), then the issue lies in the machine that had trouble finding the drive. If it disappears completely everywhere (drive + enclosure), then it's the drive or enclosure.
In general, external storage devices are typical storage devices enclosed in a plastic casing. It is possible for the electronic components inside of this casing to fail. Connecting your bare hard drive directly eliminates the potential failure of the casing itself.
Typically, both Disk Management (Windows) and Disk Utility (Mac) will recognise a drive that File Explorer cannot see (listed as RAW or Unallocated). This is a clue to the issue, however, do not take this information as instruction to perform action.
When you have identified where your drive does and doesn't appear, then you should also be able to determine most likely why this is happening and just how serious it is.
If you have determined that the drive is being recognised by File Explorer but shows no partitions (i.e. "empty" or "unformatted"), chances are good that the data is intact; it just isn't being made accessible due to damage to the disk's directory structure. Recovering data from a damaged map may be quite simple (as long as other data hasn't overwritten what needs recovery).
The drive is being recognised by File Explorer but when trying to access it, it freezes/hangs/drops off. Often times this type of behaviour occurs due to faulty sectors on the drive or if the drive has developed some sort of firmware issue. Make sure to back up any recoverable data immediately and get the drive tested to prevent further deterioration of the media.
There's no model number listed (or the model name), no capacity listed, no specs of any kind. This could be a physical problem with the hard drive itself (a bad circuit board, stuck motor, damaged heads, a dead SSD controller, etc.) which would require some level of hands-on/physical repair (ie., 'bench' work) and/or replacement parts rather than simply restarting/rebooting again.
Generally how well you’re able to retrieve your files after this point boils down to one simple fact: did anything get written to the drive after it went bad? For example, if your drive appears as RAW/unallocated then chances are good that your files are still intact, but once you initialise/format/create a new volume/write something to it using “repair” software that writes to it, you’ll begin writing over the exact info you want to recover. Many times, Windows will give you a pop-up asking if you’d like to “Format Disk.” When presented with such a prompt on a disk that contains files you desperately want to recover, do not click “Format Disk,” as doing so wipes out the critical partition structure necessary for recovery. The safe order is always the same: recover first, fix second.
The steps depend upon the type of problem that occurred with your hard drive (a hardware failure, or a logic error), and everything will be completed by us, in-house.
We verify as to whether the drive has been damaged logically (e.g., software) or mechanically (e.g., faulty boards), and whether the platters/chips remain intact. Once we have determined which condition your drive has experienced, you receive a definitive answer and a fixed, written quotation for our services prior to us doing any chargeable work.
When dealing with drives having RAW, unallocated, or corrupted file system(s), we create a read-only image of the drive and rebuild the partition/file structure from that image; subsequently, we use tools to extract the files from the image.
If a drive is absent from the BIOS, there could be many fixes. These may include repairing the board, copying/moving the ROM chip to a matching donor board, fixing the firmware, or replacing the heads (enough so to make the drive readable at least one time).
Every drive is worked off of a read-only copy of the original disk, and you receive a complete listing of what was returned prior to making any decisions about committing to recovery.
Macs hide drives for their own reasons, of course, so spend a couple of minutes on these checks before you worry about the bigger picture. First off, go into Finder and then Settings→Sidebar and General, then just make sure that you have external disks enabled to be visible. Then open Disk Utility and look under View→Show All Devices. If the device appears as greyed-out, select its volume and attempt to mount. A volume that will not mount generally means that the APFS/HFS+ structures behind the file system are damaged; however, the files themselves remain intact behind those structures, which can be a recovery job and not necessarily a dead drive. There are also two Mac-specific issues: NTFS-formatted devices from a Windows PC will appear in Finder but will be mounted read-only (thus visible, but not fully functional), and desktop-class externals tend to starve for power via an unpowered hub. Connect these devices directly to your computer instead. If neither Disk Utility nor System Report indicates that there is a drive available to be seen, then you have either a hardware issue or your enclosure’s USB bridge is faulty; in this case, take the drive to the bench and not the next available port.
The top questions we get asked when a user says that they cannot see their drive.
Generally, yes. This type of failure usually indicates that there is some sort of logical error going on with the drive, such as incorrect drive letters, RAW partitions, misconfigured drivers or storage mode settings, instead of the actual drive being physically bad. So generally speaking, the data should still be available. The only exception would be if someone lets Windows format or initialise the drive before recovering data from it.
This indicates there may be a hardware problem with one of several components: the board, the motor, the heads or, on an SSD, the controller. That doesn't mean the data has disappeared; it usually hasn't. The disk will probably need to be sent to a lab for repair. Stop switching the power on and off now and get the disk evaluated.
No, as long as there is something on the drive you would like to recover. A drive showing as RAW still has all of your data; formatting starts writing over this data. Therefore, attempt recovery prior to formatting the drive for reuse purposes.
Test using a different cable and/or port, test connecting the bare drive to another computer, and while testing, remove any external enclosure and use just the bare drive. External enclosures fail relatively frequently, and that is an easy and inexpensive fix. If you cannot see the drive directly connected to a computer system, it is likely that there exists a problem at the drive component level.
Prices for single hard disk recovery begin from £300 + VAT, and include one complimentary diagnostic. In most cases, you will not be charged unless we are able to recover your data. Where the drive needs physical work, a 50% deposit is payable towards the cost of all parts and our bench time. The remaining amount will only need to be paid if we are successful in recovering your data.
Send it to us just as it is. A free diagnostic will be carried out and we will inform you whether the problem lies within the hardware itself, or whether it is a logical fault (with the file system or partitions). We will also give you a detailed list of everything that can be recovered from the failed drive, before you spend a penny.