How to Securely Dispose of Old Computers

How to Securely Dispose of Old Computers

Getting a computer can be exciting, but what happens to the old ones? Depending on the age, some people sell them, others throw them out. That’s the easy part – the problem is the sensitive data on them. There are passwords, account numbers, license keys, customer details, medical information, tax returns, browser history…. the works.

Whether it’s for home use or business use, laptops, tablets or desktop hard drives contain a treasure trove of sensitive information that cybercriminals would love to get their hands on. Unfortunately, hitting ‘delete’ on your files doesn’t actually make them disappear, nor does waving a strong magnet over the drive. These mistakes have cost businesses millions over the years.

Why hitting ‘delete’ doesn’t help

Data on a hard drive works like a book with an index page. Every time data is written, it pops a quick entry into the index so that when you need it again, it knows where to look. The index is used for files you create as well as system files you can’t even see. Sensible, right?

Except that if you delete a file it isn’t physically deleted – it’s more like changing the index to say that nothing is on page 10 and you can write something else there when you’re ready. But if you ignore the index and manually go to page 10, you’ll find that the information is still there – the file exists until it has been written over.

The only thing that is deleted is the index reference, not the file itself.

Re-using the computer

Most people are unaware that specialized data cleanup is necessary if the computer is to be reused.

A 2016 experiment proved just how dangerous the situation can be when 200 used ex-business hard drives were purchased and 67% held unwiped, unencrypted sensitive data, including sales projection spreadsheets, CRM records, and product inventories. Frighteningly, they didn’t need any special hacking skills to get this data, it was all right there and helpfully labelled.

It’s also not surprising that with simple data recovery tools, people have also been able to access British NHS medical records and defence data, all waiting patiently on a discarded hard drive.

Wiping data before re-use or selling

Data on a hard drive can only be securely deleted if the area on the drive that contains the data, has been overwritten enough. There are specialist tools available to ‘deep-read’ a drive, so the success of overwriting a drive depends on how effectively it has been overwritten.

For example the US Defence Department requires a drive to be overwritten a number of times, including using random characters, (not just ones and zeros as some programs use) before they class the drive as securely wiped.

There are software tools you can get to do it yourself, as well as dedicated security firms, but your best option is to choose an IT business you know and trust as some software does not clear the hard drive sufficiently. With that in mind, a methodical approach is required to ensure not a single drive is left untreated as you don’t want to leave data behind, or even clues that a motivated person could extrapolate any private information from.

We can migrate any needed data, backup the information then securely wipe or destroy the hard drives for you.

Data when disposing of a computer

When we supply new computers to homes or businesses, we copy the data from the old computer and transfer it into the new one, so things like documents, photos, even internet browser favourites are in the same place on the new machine, ready to use. But the old hard drive is still there, containing all the private data that you don’t want to allow into the wrong hands, so what is the best thing to do?

We give the customer a choice. We hand the customer the old hard drive so that they can either keep the drive securely at home, or at their business – not only can they be sure that the information is still secure but this has the added benefit of having a backup copy available, should it be needed.

Alternatively, they can simply destroy the drive and the rest of the old computer can just go for recycling. Computers need to be recycled as they contain metals such as lead, mercury and cadmium which is not intended for landfill or incineration. Also there are metals (including rare and precious metals) which can be recovered.

You don’t even need special equipment to destroy it, either smash the drive or use some other method of physically destroying it, such as drilling – just be very careful! If the drive is a mechanical one with spinning platters, once damaged beyond repair it is highly likely that no-one could get to your data.

Whether you are passing on, selling or just throwing away your old computer, always bear in mind that the hard drive inside it contains important and sensitive data, so you do need to make a decision about what to do with the drive.

Need help with your old hard drives? Give us a call on 01455 209505.