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Whether you're selling it, trashing it, or reusing it, your old
computer has a bunch of extremely private data stored inside. And
there's a good chance that tossing files in the recycling bin and
hitting factory reset won't protect you. If a hacker
finds the pattern your computer used to move those 0s and 1s around,
they can reverse engineer the original state of your computer and pull
out the goods.
To stay safe, you need to properly factory reset your computer
before it ever changes hands. Follow the steps below, or consider taking
things a step further by hiring a professional company to ensure your
data has been destroyed.
What Is a Factory Reset?
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A factory reset factory reset
means deleting anything that wasn't on the device after it came out of
production, so this will definitely make it impossible for you to
practically access programs or files on your computer.
It's important to know what a factory reset actually does,
though. It puts all applications back into their original state and
removes anything that wasn't there when the computer left the factory.
That means user data from the applications will also be deleted.
However, that data will still live on the hard drive.
Factory resets are simple because they're programs included on
the computer when you first get your hands on it. It's useful to reset
errors with an operating system or helping restore the computer's
functionality or speed.
There are limitations, though. Factory resets leave data in the
hard drive, so those pieces will live on until your hard drive is
overwritten with new data. In short, the reset can give you a false
sense of security. A complete erasure would actually look more like
degaussing (destroying the magnetic field around a hard drive to destroy
its data), or actually smashing up the hard drive to bits.
Context is still key. If you only ever really played games or
finished school work on your computer, there's probably little risk in
using a factory reset as your primary form of data wiping.
But if you own a company and complete that work on a computer,
you may have employees' social security numbers on the hard drive, for
example. That means you should probably consider hiring an expert to
finish the data wiping-especially because the government has certain
standards for data sanitation, depending on the field you work in.
How to Factory Reset a Mac
- Make sure you've backed up all of your important data in a cloud service. For a primer on cloud services, click here.
- Log out of all services that you use.
- Make sure your computer is plugged in for the duration of the reset.
- Restart in Recovery Mode: Click ? and choose Restart. When the computer shuts off and powers back on, hold Command + R until you see the Apple logo.
- You won't see your usual login page, anymore, but instead will see a "macOS Utilities" window.
- Choose disk utility > continue.
- Choose the correct startup disc and select erase.
- Choose MacOS Extended (Journaled) as the format.
- Click erase
- Wait until the process finishes, then go to the Disk Utility menu > quit.
- If you like, reinstall MacOS.
How to Factory Reset a PC
- Repeat steps 1-3 as listed above.
- Navigate to Settings > Update & Security > Recovery. You should see a title that says "Reset this PC." Click Get Started.
can either select Keep My Files or Remove Everything. The former resets
your options to default and removes uninstalled apps, like browsers,
but keeps your data intact. The latter, as its name suggests, will
delete your files. In either case, back up your files in case something
- Use the Fresh Start option in
Windows 10: Settings > Update & Security > Recovery page,
Then, click the link text "Learn how to start fresh with a clean
installation of Windows at the bottom. That opens a Windows Defender
Security Center window to the Fresh Start option. Click Get started.
Why a Reset Sometimes Isn't Enough
Inside your hard drive
are two rotating discs that sort of resemble a CD. These are called
platters, and they're the pieces of hardware that actually store all of
those cat videos and family photos.
stores data onto its circular surface in chunks of 1s and 0s. Platters
are usually ceramic, glass, or aluminum, and work like a record player.
Centered on a spindle, the platter rotates and an electronic current
reads and writes data onto the surface. Electronic components power the
When you delete data from the computer through a factory reset,
the information is hidden from the computer, but still stored on the
hard drive. If a hacker uses data forensics tools,
they can find bits and pieces of those deleted files in the hard drive
storage, making it possible to recover pretty much everything.
There's much online debate about the best ways to completely
destroy the data inside, but most solutions come down to water,
hydrochloric acid, magnets, or a blunt object you can smash them with
These methods might sound hardcore, but three of them still
aren't completely reliable. Microwaves often don't get hot enough to
properly wipe the platters. Acid doesn't seep deeply enough inside the
discs to ensure complete destruction. Hackers have recovered laptops thrown into bodies of water and dug data out of the hard drive afterward. Magnets aren't always strong enough.
But smashing the platters is a different story. Just make sure
you wear safety glasses, because the platters often break into tiny
shards when smashed. Remember: the key to destroying the platter
properly is ensuring it can't spin. If it can't do that, the platter's
contents can't be read.
If you do want to reuse the hard drive, a factory reset should
be your course of action. As stated above, first be sure you don't have
any comprising information on the hard drive, because it could take a
long time for new data to overwrite all of the old data on the drive.
Solid State Drives
Screenshot/Data Security, Inc.
While there's a pretty decent chance the old computer you want
to nix has a hard drive disc (as it's an older, slower form of data
storage), newer computers are fast adopting a new standard called a solid state drive, or SSD. These contain the microchips you may picture inside of your phone against a green circuit board.
A solid state drive is essentially a larger and more
sophisticated version of a flash drive. Information is stored on
microchips and contains no moving platters. This kind of drive also
doesn't have magnetic coatings like a hard drive disc. Rather, solid
state drives have an embedded processor, its "brain," and interconnected
memory chips that retain data.
To destroy a solid state drive, you can't use a degausser,
because there's no magnetic storage. Instead, you should physically
destroy the device with something like the SSMD-2MM Solid State Media Disintegrator,
which is something professional data destruction companies should have.
It essentially shreds up your hard drive until it's in no way
How to Tell If You Have a Solid State Drive
press the Windows key + R to open the run box. Type in "dfrgui" and
then press Enter. When the Disk Defragmenter window pops up, check the
media type column to find out if you have an SSD or an HDD.
On Macbook: select the ? menu > About This Mac > System Report > Hardware > Storage.
Otherwise, you can take the computer apart to check. If you
don't routinely work on this hardware, though, you're better off
checking out your hardware through the software menus.
How Do I Recycle My Computer?
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After you've wiped your drive and smashed your computer, you
must find a specialty recycling company that will take the parts. In
other words, don't put glass shards, aluminum, and plastic from the
device into your recycling bin. Sure, the trash person may pick it up,
but it's just going to end up in a landfill because general recycling
facilities don't have the capability to reuse these parts.
Below are just a few places you can send your devices if they're
intact and you've only done a software wipe. Some places will give you
cash for the computer, and other places will do the destroying for you.
This company specializes in data destruction, so if you've done a
factory reset on your laptop, but you haven't bothered to destroy or at
least take out your hard drive, CyberCrunch will handle that for you. In
fact, it's part of the company's recycling process. Rates aren't
disclosed on the website, so you'll have to call. Simply mail in your
device and it will be securely recycled.
As far as corporate companies that offer electronics recycling go, this
is one of your best options, since Best Buy has a wide span of stores.
The store will let you recycle three items per household per day for
free, and you can even check out the company's trade-in program to see if you'll get any money for it.
So far, Best Buy has "responsibly disposed" of more than one
billion pounds of electronic waste, which the company claims makes it
the largest retail collection program in the country. The company is
working with certified partners to reach two billion pounds.
Whether a full-fledged enterprise company or an individual consumer,
this organization will help you find a local place to take your
electronic junk, as it's part of a global mission. Through its "Find a Recycler" tool, simply enter your country, state, and zip code to find recycling shops nearby.