The quick answer is that it hinges entirely on where your data is stored. On a traditional spinning hard drive the answer is no, and not by a narrow margin: the files come straight back with free tools. On an SSD the data usually does go, though as a fluke rather than by intent. On a phone it genuinely does. And if you are about to sell or scrap a device, that distinction is everything.
When you do a factory reset, what gets erased is the index, not the files themselves. Whether the data survives then depends on the type of storage your device uses: a hard drive holds onto it, flash tends to clear it out automatically behind the scenes, and a phone discards the key.
It is probably the most expensive myth in everyday computing, and people use it as a crutch every day.
However you describe it (a factory reset, Windows’ “Reset this PC” or a quick format), it amounts to the same thing: the file system’s index is stripped out and the disk is marked as empty. The data stays put. Every file, every picture and every stored password is still on the platters where it was first written, in the very same blocks, and perfectly readable.
Any free recovery utility will lift the data straight back off the drive, without requiring any expertise: an afternoon and no real skill is all it takes. It is the same routine process as recovering ordinary deleted files. Sold or gave someone your laptop with a spinning drive after “wiping” it this way? Whoever received it now holds your files, whether they know it or not.
With SSDs it is a completely different situation, due to TRIM.
Once a factory reset or format marks an SSD’s blocks as unused, the drive’s garbage collection wipes those cells for real in the background, frequently within minutes, whatever else the machine is doing. So when an SSD is reset, the data genuinely goes away, and getting it back really is a long shot.
Be clear on what that is, however: a by-product of how flash levels out wear, not a security feature. It is unverified, uncertified and no basis for a GDPR position. Nothing signals that it finished, and nothing provides evidence that it ran at all. It is fine for selling an old laptop online, but certainly not for any machine that stored client records.
Modern smartphones are the one exception, and here the design is sound.
Because today’s iPhones and Android handsets encrypt their internal storage out of the box, a factory reset deletes the encryption key rather than attempting to erase the data. With the key gone, the data is mathematically out of reach, and the fact that it physically remains on the phone is irrelevant. That is a sound approach, and it is exactly why an encrypted laptop can also be reset safely.
It is also why we don’t take on phone recoveries: that is an entirely separate craft, and we would rather decline the job than handle it poorly.
Hit reset by mistake? Whether your data comes back falls into the same three categories.
On a spinning hard drive, usually yes, and often completely, because the reset only drops the file system’s index. The main thing is speed: stop using the drive at once, because any new writes could land on the blocks still holding your old files. That is a routine single-drive recovery, from £300 +VAT once we have run a free diagnostic. On an SSD, usually not, as TRIM has most likely cleared the cells by now. On a phone, no, because the key is already gone. Reset a drive holding something you cannot replace? Switch it off and get a straight diagnostic before another byte is written.
For everyday malware infections, yes, apart from a handful of genuine exceptions.
Resetting reinstalls the operating system and deletes the user partition, where the vast majority of malware resides, so a reset usually sees off everyday infections. The exceptions are worth keeping in mind, however. Malware lodged in firmware or a hidden recovery partition can survive a reset, and the classic way people become reinfected is by restoring an infected backup immediately afterwards. Reset first, then rebuild from data you know is clean, and you are on firm footing. Stubborn or business-critical cases warrant proper virus and malware recovery.
There are four scenarios where “I ran a factory reset” will not suffice.
Selling a laptop that has a hard drive? A quick reset will not be enough: the disk needs to be properly overwritten or physically destroyed. Retiring business kit? Under UK GDPR, you have to show that personal data was disposed of correctly, and “we ran a factory reset” proves nothing; what you need is a certificate listing the drive serial numbers. Throwing out a failed drive? A disk that will not boot is not a disk that cannot be read: failed drives are exactly what we recover day in, day out, and so can anyone who pulls one out of a skip. Encrypt from day one, honestly the simplest fix: if BitLocker or FileVault has been on since the machine was new, a reset destroys the key and the data goes with it. When disposal has to stand up to scrutiny, our certified data destruction service provides erasure or physical destruction backed by a certificate.
It depends on the type of drive fitted. With a mechanical hard drive, no: the factory reset only deletes the index, and free tools can bring the files back. With an SSD, usually yes, due to TRIM, which clears the cells in the background. Either way, a reset alone is no guarantee of erasure, so don’t rely on it when selling or disposing of hardware.
Often, on a hard drive, and frequently in full, because the factory reset only deleted the index. Stop using the drive immediately so that nothing overwrites the original data, then get a diagnostic; that is a routine single-drive recovery from £300 +VAT. On an SSD, the data is usually lost to TRIM, and on a phone it is lost with the encryption key.
Yes. Modern phones encrypt their storage as standard, so resetting one deletes the encryption key rather than scrubbing the data. Without the key, the data cannot be reached mathematically, which is why a reset genuinely removes data from a phone, unlike on a spinning hard drive.
Generally, yes, for the most common cases: the reset reinstalls the OS and clears the partition where most malware lives. What survives is malware buried in firmware or a hidden recovery partition, and restoring an infected backup afterwards simply reinfects the computer. Reset, then rebuild from a source you are certain is clean.
No. A reset is not a certified wipe: on a spinning hard disk everything remains recoverable, and while a reset may wipe an SSD, the erasure is an unverified side effect with no confirmation that it actually took place. Selling safely or meeting a GDPR disposal duty requires a verified overwrite or physical destruction of the disks, along with a certificate listing the drive serial numbers.
There are two reliable routes. The first is to use full-disk encryption from day one: with BitLocker or FileVault on from new, a reset discards the key and the data with it. The second, for a drive left unencrypted, is to overwrite it properly or have it physically destroyed. On a mechanical hard disk, a reset by itself is never sufficient.
If you need to clear out business equipment, or you want to sell a computer that held sensitive data, we will wipe or physically destroy the drives and issue you a certificate bearing the serial numbers: the proof a factory reset simply cannot give.