/ Technology

Do you always erase your personal data on old devices?


Last year, my flat was burgled. I was only just in the process of moving in, and so they got barely anything for their efforts apart from three battered laptops. 

These machines were near relics. One hadn’t been turned on for years, the other two didn’t turn on at all. I kept them in a mix of laziness and fear that they still held fragments of data.

At some point, I intended to safely erase this data. Problem is, now I will never know where it’s gone.

Data dread

Putting aside my skittish paranoia, the likelihood is those laptops ended up in the bin. I can’t see anyone wanting to buy them, or viewing it a worthwhile endeavour to recover the hard drives.

However, I’m kicking myself that I didn’t just wipe the machines when I had the chance, and maybe even sold them when they did have some value.

Even those who do sell their devices don’t always wipe them.

In 2014, researchers at security firm Avast extracted a mind-boggling 40,000 photos from just 20 Android phones it bought on eBay, including over 1,000 featuring nudity.

Our investigation into deleting personal data

As featured in the latest edition of Which? magazine, we sent Android and iOS smartphones and tablets, along with PC and Mac laptops, off to specialist data recovery lab, Kroll Ontrack, to see what data was left on them.

The good news is the majority of devices in our snapshot research were clear of data. However,¬†a few still had personal emails, photos, text messages and documents left on them. It was clear that they hadn’t been wiped properly.

You can make hundreds of pounds selling an old phone, tablet or laptop, so it’s a great thing to do when you’re ready to upgrade.

Just¬†follow our guide¬†to ensure an Android, iOS, Mac or PC gadget is wiped so you aren’t left with a lingering sense of data dread.

Have you sold on a device? Was deleting personal data upmost in your mind? Or have you bought a second-hand gadget and found information or photos left on it?


My “old devices”, including hard drives, get retired with a very large mallet followed by a dunking in engine oil. They are never, ever, sold.

I have sometimes acquired 2nd hand devices with previous users’ data on them.

If am I selling, or giving away, old devices, I usually do my best to wipe any data off them.

Sorry to say the normal wiping available to the public doesnt really do the job , they can still hold data and the old hard drives could be pulled apart and interrogated with digital electronic equipment . To really remove it requires a professional app which you have to pay for its then issued with a certificate of erasure and the new SSD,s require an even better one —that costs ,so your -download it for free from the web just doesnt “cut the mustard ” . Tool for guaranteeing removal of data — sledgehammer , making sure ALL the chips are smashed to powder.

It’s amazing that many still believe that simply deleting files will destroy them.

Were applicable, old hard drives are removed and placed in a portable caddy.

Yes William , Maplin have sold them for years I have several used as external storage ,on, not just my computer but on my satellite box , works just fine got over 200 films on it , better watch out for the copyright squad got some from countries that show up to date films —for Free . .

I have re-formatted a one or two hard drives with a lump hammer but have quite a collection of old laptops and external hard drives going back to the 90s. One of the reasons I hold on to the laptops is because newer computers can’t open some of the old files.

That re-formatting,s hard on the wrist Wavechange, isn’t it ?

Especially when you go back and have a second go …… and a third just to be sure. ūüôā

Ha ! Ha ! Ha! -very good Wavechange . Your mind has the same “redirection ” as mine –always make sure .

Where you have full (or enough) control of your PC(s), you can always opt to have all your files or you entire disc fully encrypted.

This is likely to make it impossible for any casual recipient (of cast off or purloined devices) to read any of your files. Any paranoid readers may wish to consider that the security services might be able to crack some of the less complex encryption schemes.

The downside to using encryption is that you may need to keep separate copies of your passwords and/or encryption keys elsewhere. Otherwise, if your PC fails but its disc is still OK, you won’t be able to easily recover your data on another PC.

Any “paranoid” readers Derek , maybe more like deeply informed of the workings of the security services in the west . You do know the power of the US computers ,dont you ? But you have a point, one of my secure email services ( end to end encryption ) which I have in case of emergency was attacked it was known very publicly, well at least in the security world , by “western security” (no names , no pack drill ) in a DDoS attack taking it out for a short time , so yes good encryption has its uses but you also know our own GCHQ advises against it , “keep it simple lads ” I remember that comment that will live forever in many knowledgeable peoples minds . its when they take they huff you have to worry about , I always keep a spare computer handy , they like a joke but when they dont get their way the child comes out/school bully.

I join the destruction brigade and never part with any computer type product until the storage system
has been removed. If I can’t identify where that is, in something solid state, the appliance gets mashed before going to the skip. I usually take the “useful” information from the old device and put it on the new one as a file in memory. I access this far less than I thought I might, but the old photos and creative writing can not be replaced. One day I’ll find time to weed out the junk and put the rest on a stick in some kind of order….one day. Slightly off topic, I am still shocked at the vast mountains of discarded electronics that have ended up in China and the awful sight of individuals taking bits and knocking off the precious metals for a living. It brings back memories of Dickens and the dust mountains in “Our Mutual Friend.” We really know how to pollute our world.

I-M L says:
3 December 2016

Should we not be advised to wipe data when buying or taking over second-hand computers or gadgets? They could contain illegal images or show access to illegal material on the internet, and it may be very difficult, or even impossible, to prove that this was nothing to do with yourself, in case of a police investigation.

Thats the problem I-M L, I bought a second hand PC at a car-boot sale there were pictures of a naked married couple —-well I wont go into it. If I took that to the police I would be arrested , my name would be mud , jailed etc.

Well, the photos or access logs will be dated, so you wouldn’t have a lot to worry about. But given the low cost of HDs, now, I’d err on the side of caution and simply install new drives. I re-use all old drives until they’re failing, then physically dismantle them and render the platters incapable of being read.

Can you really be sure that the dates etc will be correct? Occasionally, my own computers dates have reset itself to a different year/time.

Ing-Marie- this is more serious than you think , while it could be a driver update is needed or the CMOS battery is running low , it could be a virus , as, if you are using windows, security updates will not download typical of a viral action .Have you downloaded anything recently from the three social websites ? If not I could help you through a check on your computer , are you using Windows protection ? I could recommend others although this type of virus isnt easy to spot . But it could very well be your CMOS battery which should be 3 volts / circular /shiny /flat -disc looking in your computer , some last many years others only a few years. I would certainly not leave this as you would be open to attack on a Windows system.

Ing-Marie: while it’s true that dates might be incorrect, modern computers depend for their overall functionality on correct and accurate dating and actually altering the attributes can interfere with other aspects of the system. However, overall you’re right: they can be altered.

Thanks for reply, Duncan. I’m on a new computer now, because I just gave up on getting the old one back to usable and that was the one where the date got reset. I actually put the main problem down to the Windows 10 Anniversary update. A number of drivers on my PC weren’t compatible, apparently. I eventually manage to do a factory reset, but then I got a hard drive error warning, was unable to open Windows, again, and by that time, I’d had enough! The idea of virus did enter my mind, and maybe it was both a driver problem and a virus. I can’t remember if I just had the security that comes with Windows 10 (I had upgraded from 8.1) or if I had installed a security suite.

I would need to do some further training to manage that, Ian!

Thanks for replying Ing-Marie- not many do , if its a new PC we can rule out the battery and your dead right , unless Windows 10 Anniversary Update ” approves ALL the drivers it blocks you from booting up and logging on . Its also not too happy about you installing a good paid for virus control system as it tries to manipulate it as it does so much spying . I would advise you to pay for a good PC+ full Internet protection suite but meanwhile are you using Edge browser or Internet Explorer ? If I was you I would install Firefox as you can add a whole host of protection apps to it , thats the main use one I use , these will block this type of “click on a virus” thing I have already tested it out and it works .But knowing MS they might block some of them as many people dont realise the Windows versions of browsers arent the same as other systems like the LInux one I run which I control not MS . At the moment 53 % of Windows users Worldwide use Win 7 and 32 % use Win 10 ( latest figures from MS ) but you shouldn’t believe everything MS says they don’t even mention XP although about 12 % still use it. Try installing Firefox ( if MS will let you ? ) .

It’s not hard, Ing-Marie. You do need a specialist tool kit to open the old drive, but once in a hammer and pliers quickly render the platters (where the data’s stored) utterly unusable.

Yes I would second that Ian.

“it may be very difficult, or even impossible, to prove that this was nothing to do with yourself, in case of a police investigation.”

er, hold on a moment, whatever happened to “innocent until proven guilty” ???

Thats what worries me Derek .

Ing-Marie says:
3 December 2016

I think that your life can be shredded into little bits, while “innocent until proven guilty”.

That’s both concise and totally accurate.

Quite so, and under the ancient doctrine we are only “presumed” innocent until proven guilty, in other words whoever accuses us can believe we are guilty but the court has to give us the presumption of innocence in order for the case to proceed. But nobody comes out of a trial as innocent – the best you can get is “not guilty”.