The drive that vanished last night is almost certainly still holding every file it held yesterday. What decides the week is where it went: listed in Disk Management with no letter beside it, or absent from the BIOS as well. One of those is a filing problem. The other is hardware.
£300 + VAT covers one drive or SSD, NVMe included. Nothing is charged for the diagnostic, which closes 2 working days after the drive lands in Guildford. Logical faults keep no fix, no fee; a dead board or a failed head takes 50% up front.
Plugging it in for a ninth time tells you nothing. Two screens do: Disk Management on Windows, Disk Utility on a Mac. These are the six positions people ring about from Bracknell and the towns around it, roughly in the order they turn up.
The capacity is right and the model name is right, and there is either no letter beside the volume or the word RAW where NTFS should be. Nothing mechanical is wrong with it. Something that records where the files begin has been damaged instead, and this is the cheapest position anybody on this page can be in.
Say no. Initialising writes a fresh, empty partition table over the one describing where your data lives, and it arrives in a dialog box that looks entirely routine. Choose Cancel, close Disk Management, unplug the drive and stop there. That one click separates a short job from a long one.
Windows can see the disk perfectly well and cannot make sense of the file system on it. Boot sectors, the master file table or the directory tree have been corrupted, often by a cable pulled out mid-write. The files are still on the platters, and running chkdsk at this point is what buries them.
The machine cannot see a device at all, which puts the fault in the electronics, the firmware or the mechanics rather than in the filing. A drive that stays silent, one that spins up and stops, and one that reaches the desktop then vanishes under load all belong in this group.
In Disk Utility, switch on Show All Devices from the View menu first. A greyed-out device with a greyed volume indented under it means the hardware is fine and the volume is not. No device row at all means the Mac is seeing nothing. Decline the offer of First Aid until the disk has been copied.
The drive mounts, copies for a minute or two and disappears, or the connection noise repeats every few seconds. That is usually weak sectors stalling the interface, a tired USB bridge, or a 3.5 inch disk on a supply that cannot hold it. Every retry is more running time on a drive asking to be left alone.
On Windows 10 and Windows 11, hold the Windows key and press X, then choose Disk Management and give it a moment to finish listing. If your disk appears there at the correct capacity, the hardware is talking and the trouble sits above it: a lost partition table, a volume with no letter, a partition marked RAW. If it is absent, restart and look in the BIOS or UEFI setup instead. A disk missing from there as well is beyond the reach of any software on that machine, because there is nothing for Windows to attach itself to.
Handing the volume a letter is the one step on this page that cannot make anything worse, so where a healthy volume has simply been lettered wrongly, right-click it, pick Change Drive Letter and Paths from the menu, and hand it a letter nothing else is using. Everything else in that window writes to the disk. Format, delete volume, new simple volume and initialise are all destructive, and all of them sit two clicks from where you are standing.
Disk Utility shows mountable volumes by default and hides the physical device, which is precisely the wrong view when a disk refuses to mount. Open the View menu, choose Show All Devices, and the list becomes two levels deep: the device on top, the container or volume indented beneath it. A greyed volume under a healthy device is the Mac version of the RAW partition above. Where the device itself has gone, look in System Information under Storage and USB before writing the drive off, because a failing enclosure hides a working disk more often than people expect.
External drives fail at the case as readily as at the disk. Try another lead, another port and a different computer, in that order, and use the ports on the back of a desktop rather than the front. What does not follow is that the disk inside a My Passport or a Backup Plus can be lifted into a spare caddy: a good number of those bridge boards encrypt everything passing through them, so the bare drive reads as noise in any other enclosure. Where that is the fault, the case needs to travel with the drive. The wider picture for cased drives sits on the external drive recovery page.
A partition table is a short list kept at the very front of the disk, recording which volume begins at which address and how far each one runs. A few kilobytes describe several terabytes. Lose it and every file remains exactly where it was written; only the index that finds them has gone. Initialising writes a new and empty version of that list, and on a GPT disk it replaces the backup copy at the far end of the platter too, so the very structures a recovery would have used to rebuild the map are the ones destroyed. What is underneath usually survives even that, but the job gets slower, the results get patchier, and none of it needed to happen.
The repair tools deserve the same caution. chkdsk with the fix switch rewrites file system metadata on a volume it assumes is fundamentally sound, and on a disk with failing sectors it tidies the damage into a neater arrangement instead. Folders readable an hour earlier come back empty, their contents renamed as numbered fragments. Recovery software installed onto the affected drive does its own harm, because every write lands in the free space where the missing content is waiting.
A disk missing from the BIOS is a hardware conversation, and there are three common answers. The board: a blown protection diode after a bad power supply, a cracked track, a failed motor driver. The firmware: the service area on the platters holds the tables a drive needs in order to describe itself, and one corrupted module leaves a mechanically perfect disk unable to say what it is. Or the mechanics, which means clean bench work with a donor. All three look identical from the outside, and that is exactly why the diagnostic is free and the figure follows it rather than preceding it.
The terms track the fault rather than the symptom. Firmware repair keeps no fix, no fee. Board-level and chip-level work does not, and neither does anything mechanical; both take 50% of the quoted figure up front, because donor hardware is bought for your drive and for nothing else. The line behind all of it is the same one used across this site: no fix, no fee all jobs except electronic and mechanical failures, chip level work, DVR and Forensic jobs.
Flash storage disappears in its own way. An SSD whose controller has dropped into a safe mode shows no capacity at all, or turns up as a device of a few megabytes with a generic manufacturer name. There is no noise and no warning, and yesterday it worked. NVMe drives in thin laptops sometimes vanish only once they are warm. A USB stick that lights up and never appears is usually a dead controller rather than dead memory, and the chips are read directly in that case. Sticks and cards sit at £250 + VAT. One hard drive, SSD or NVMe module is £300 + VAT, and neither figure moves once it has been written down. Every band is published on the data recovery cost page, VAT shown separately.
Send the drive by itself rather than the laptop or tower it came out of, and include the external case where the fault might be in the case. Media goes to Guildford Data Recovery, Building 2, Ground Floor, Guildford Business Park, Guildford GU2 8XH, about 40 minutes down the A322 and the A3 by car, and next working day by tracked post. Reception there takes drop-offs during office hours. Nobody in this network collects, and Bracknell has no counter of its own, so the post is how nearly everything arrives. The free diagnostic closes 2 working days after booking in, never sooner, and the quickest finished recoveries run 2 to 4 working days from approval. Phones and tablets are outside what this lab handles.
Cancel the initialise prompt, unplug it, and let a free diagnostic say what it is. The figure arrives in writing first.
Almost every drive on this bench arrived in a padded box. Tracked post is the gentlest way to move a disk that is already in trouble, and a parcel handed in around Bracknell is usually in Guildford the next working day.
Is the storage still bolted into a machine — laptop, tower, iMac, MacBook, rack server, a DVR under the till? Free it first and send the bare unit. Stripping hardware is not something this lab does, though it is ten minutes' work for any repair shop on your high street. There is a single case with no way round it: memory chips soldered flat onto the mainboard, which is how Apple Silicon machines and certain ultrabooks are built. Where the storage cannot be unbolted, there is no parcel to make up.
↓ Print the shipping & booking-in form (PDF)
The name on the parcel wants to be Guildford Data Recovery. Driving it over from Bracknell is roughly forty minutes on the A322 then the A3; posting it costs you a stamp and a day. Either way, a message goes out to you as soon as it is logged onto the system, and two working days later the diagnostic is finished.
Unsure whether something should go in the box? Ring 0800 689 0668 while the lid is still open, or work through the free online diagnostic and let it tell you.