What is the best way to safely and completely erase all data from old laptops?
I have a couple of old laptops lying around and want to throw them away, but have been cautious to do so because of privacy concerns of data still on the hard drives. What is the best way to wipe them? Or should I take them out and physically destroy them?
I don’t see how much data can be recovered from broken, bent pieces. If you’re really concerned, you can use a torch to raise a magnetic platter until it glows, this raises it above it’s curie temperature so all the magnetic particles stop being magnetic.
It takes far more work to recover data off of smashed platters than Joe the average users data is worth. There’s very few ways to make that data completely nonrecoverable. Even zeroing the drive isn’t 100% safe from someone with the right resources and knowhow. Just smashing the platters makes data recovery enough of a pain that it’s almost never worth it.
Data on a HDD that’s been overwritten with zeros or random data is unrecoverable with all known current technology.
In theory it might be possible to recover something with some future tech that hasn’t been invented yet, which is why the DOD standard requires erasing with multiple passes, but there isn’t currently a (publicly known) way of doing it.
SSDs are a bit tricky because of wear levelling, but usually two full overwrites of a SSD makes it just as unrecoverable.
It depends how badly you need that data to never see the light of day again. Most likely, you’ll be fine to erase the drives with secure erase options (where it writes 0 and then 1 to the whole drive, and back and forth a few times depending on settings), but if you really really need to 100% guarantee there’s absolutely no chance of recovery, then you’ll need to destroy the drives physically
In that case, secure wipe should be more than enough
also, if you’re getting rid of them, there might be a charity you can donate them to rather than just tossing them. Idk any off the top of my head, but it seems worth looking into
Hammer, then marinate for atleast 30 mins in soya sauce, onion, garlic, herbs, then bbq, eat and poop in 3 different bathrooms across the city. Pro tip, sprinkle with olive oil each side while on the grill.
If you just do the simple one-pass zero-ing out, suggested a few times here, the data is only recoverable in theory. There are labs that do it, but they charge thousands of USD for a drive and giving limited results.
Unless you are being actively targeted by deep pockets, that’s plenty good enough.
I work at an electronics recycling facility and all laptops that are recycled are completely sanitized and properly disposed of as e-waste. Look around for a local recycling center and check for an R-2 certification, if they have one they will take out any identifiers and do passes on drives via a sanitization device to ensure that the whole thing is completely devoid of all data.
Geez at the answers in the thread. Boot off a USB drive with Linux, right click the HD, and simply format the drive. Not a quick format, you may have to unselect that. You’ll know because a quick format will take seconds, a full format will take an hour (depending on the size of course).
Then donate the laptops. Donation place should be able to install Linux. Most people don’t need much laptop.
Hmm, what does that full format do? Write zeros over everything?
Personally, I would run shred on the root filesystem. It’s a tool specifically intended for properly deleting data (overwrites it with random data multiple times).
The easiest options in order of effectiveness, and how to bypass them:
Do nothing.
Reset Windows or erase all files you don’t want to be found. To recover from this you need a specialised piece of software that will recover the files, but not the names or locations, so while the actual data is easily recoverable, the person would need to sieve through most files you’ve had in your PC since forever with no order.
Zero the disk, my way to do this would be to boot a Linux USB and run for example dd if=/dev/zero of=/dev/sda, this will delete EVERYTHING on that disk, including windows, partition table and the bootloader. The way to recover from this involves specific hardware and a sterile lab, unless the authorities are investigating you it’s very unlikely someone will recover from this.
Multiple passes with zeroes and random data, the way I would do this is the same as above but use /dev/urandom for the if parameter, run it multiple times, then run once with zeroes. Theoretically it could be possible for the same lab as before to recover some data if the machine ran out of entropy and didn’t wrote actual random data, and someone could predict the random data and compensate for it on the residual magnetic field, but it’s highly unlikely. Almost no one would be able to recover this, and if someone can they will charge A LOT.
Physical destruction, e.g. drill a hole or smash the disk for an HDD, break the chips for an SSD.
All of that being said, why throw it away? Why not sell it or use it to self-host something cool like a media centre or a steam machine if the laptop is good enough.
You’ve said you’re intending to throw these laptops away, so physical destruction is quickest and simplest.
But, if you’re intending to sell or give these away for someone else to use, zeroing each sector is probably ‘good enough’ for your purpose (as someone else has always said).
If you really want to make it harder, you can use something like the Boot and Nuke bootable Linux disk for the job, as it also has the option of multiple passes, using zeroing and/or binary random shit for each sector. Just grab the free for personal use version.
Unfortunately the degausing trick doesn’t work that well with newer higher capacity harddrives. As capacity increases they actually need to be less sensitive to magnetic fields to prevent multiple bits flipping when the drive head tries to write data. With modern multiterabyte harddrives you’re going to have a hard time reliably wiping the platters with anything short of an MRI magnetic field. That’s not to say smaller magnetic fields like degausing coils can’t be damaging; they will just take a long time to destroy enough of the data to prevent recovery. You’re actually more likely to break the drive heads with a degausing coil than you are to wipe the platters.
'zeroing' every sector is probably 'good enough' for mechanical hard drives.
if the laptops are functional:
boot a target laptop to a windows install disk or usb. at the first prompt, hit SHIFT-F10 to open a command window.
diskpart
list disk
select disk 0
(laptop internal drive should be disk 0)
clean all
(this will take time. on an older laptop, up to maybe an hour per 250gb of hdd capacity.)
exit
power off.
if they're NOT functional laptops:
remove the hdd (search the make and model at yt for guides), connect to another pc (via usb adapter) or internal inside a dt. boot to that system's normal windows, run diskpart from an admin command prompt.. do the same as above but note that in this case: IT WON'T BE DISK 0 -- be sure to 'select' the correct disk
if one of them happens to be an ssd. instead of wiping it (this method isn't for ssd, btw), get an enclosure for it (as little as $8-10) and use it as an external disk.
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