Wiping data question before selling

[indidginus]

Hello all,

I have an r61e that I have done a full restore on using the thinkvantage button on boot, so it now has a clean windows xp install. I'd just like to confirm that all my personal data is completely gone from the computer before I sell it, so that there is no way of using a program to recover it or anything like that. Does the full restore take care of that? Many thanks for your help.

Michael.

[axur-delmeria]

IMO the best way is to wipe the disk yourself, then do a clean install of the operating system afterwards.

For wiping, you can use DBAN, killdisk, or even just a Linux live CD or USB-- IIRC the Ubuntu Live CD image has the dd command, which can be used to erase disks.

[theterminator93]

Depending how much of a guarantee you want against all possible scenarios, simple full-format zeroing wipes of the entire disk may or may not meet your needs. With a simple zeroing pass, that will prevent the vast majority of recovery applications from being able to read sectors and reconstruct data. But there are ways with more advanced tools to reconstruct zeroed blocks using residual magnetic traces. So a multi-pass, structured non-zero write (e.g. a DoD compliant wipe) is the best way to guarantee no recovery of data.

[kfzhu1229]

For normal folks out here a zeroing wipe is good enough. But if it's an SSD we are talking about here, a zeroing wipe adds a lot of total write counts onto the SMART value and the lifespan of a ssd greatly depends on how much write cycles it is performed to the drive.
For laptops that came out of some business environment (especially the ones involving with a lot of confidential data), some might even consider selling it with a different hard drive altogether. This is why many business class laptops on eBay are sold with no hard drives (and no caddies because those ppl simply don't have time to figure out how to remove the drive from the caddy).

[axur-delmeria]

But there are ways with more advanced tools to reconstruct zeroed blocks using residual magnetic traces. So a multi-pass, structured non-zero write (e.g. a DoD compliant wipe) is the best way to guarantee no recovery of data.

Once I erased an HDD using the Linux dd command with /dev/urandom as input.
It was a desktop 80GB drive so it didn't take too long.

A full disk write heats up the HDD tremendously, so I haven't tried multi-pass wiping. If I ever try it, I'll probably let the HDD rest for at least an hour between each pass.

[Cigarguy]

For most people, and companies for that matter, secure erase is more than sufficient. If you really have super duper sensitive porn data then sell the laptop without that particular HDD/SSD.

The most unrecoverable way of erasing data is to remove the platters from a HDD or PCB from a SSD, smash it into tiny pieces with a hammer, then throw everything into a fire. Makes for some interesting sparks. The magnets from a HDD makes a wonderful tool for magnetizing screwdrivers.

[axur-delmeria]

The most unrecoverable way of erasing data is to remove the platters from a HDD or PCB from a SSD, smash it into tiny pieces with a hammer, then throw everything into a fire. Makes for some interesting sparks.

I thought there was a "soak the platters in acid" step in between.

[MikalE]

.45ACP will do the same thing in a lot less time.

[indidginus]

Thanks very much for your input everyone. Is a secure wipe the same thing as the factory reset/full restore in ThinkVantage startup settings?

[axur-delmeria]

Thanks very much for your input everyone. Is a secure wipe the same thing as the factory reset/full restore in ThinkVantage startup settings?

Most likely no.

[theterminator93]

No, a full restore from the recovery partition/software will just restore the disk image to the boot partition. It will just write over any sectors with the original image data; it won't clear any of the unused sectors. You could do a full format of the partition before doing that, to get to that erased "well enough" point to prevent 99.99% of users from being able to read the unused sectors.

[xelonakias]

The most despairing thing about data wiping.

Really nobody cares about your porn data.
Even if they do stumble upon it, even pictures of your baby finally managing to walk for the first time, they'll just erase it, getting more space for that zuzanna_big_t***.AVI / tax_return_done_quickly_no_malaware_cr3t1n$.docXXX file...

And that folks is the bitter truth. Our life data matter little. Our buying habits data, are sellable.

(morose music)

[Vopu]

Windows based restore/erase/reset will not completely erase the data rather replace/re-pass/marks the data space as empty so it can be over-written with new data. Meaning it can also be recovered by special data recovery sw. Some erase sw also does this but instead over writes space with "000"'s, which is as mentioned by others safe/secure enough for the average user. To make sure data can _never_ be recovered , you need a more physical aproach as either witholding the drive from sale , or destroying the drive itself. Certain sw programs claim to continiously over-write data to a specific set figure, forcing the recovery sw to try to trace the data on a drive that has not been erased only but data space over-written randomly multiple times with random symbols.This makes both the process of recovering , time spent and also if a successful recovery can be performed the data recovered will be corrupted.
One such method is Gutmann method , to replace/over-write(not only with 0's but random data) data with 35 passes. DBAN mentioned here is one such method, CBL and Disk Wipe other examples. For file deletion only/(not entire disk) CCleaner /eraser.heidi uses the same method.
As everyone asked, one question comes to mind as how precious/absurd/offensive your collection of "books" on that drive is.
Also why is it one always thinks of porn when question of secure erase data comes to mind/arises Surely there are still some legitimate national geographic documentaries floating around
I think i will finish with one golden rule we were thought back in the day. A digital data can never be completely erased.Traces will always be present.
Vopu

[atagunov]

If it's an SSD, a secure erase is what I'd suggest. It benefits both you - your data is - well is at least well hidden - if not outright destroyed. An intelligence agency would probably be able to recover it but your buyer almost certainly will not.. It also benefits the buyer - the whole of SSD is marked as free and that restores SSD speed to that of a new disk. One way to do secure erase is Try Ubuntu from an Ubuntu installation USB. "hdparm" commands, should be available on many places on the internet.

[cadillacmike68]

The most despairing thing about data wiping.

Really nobody cares about your porn data.
Even if they do stumble upon it, even pictures of your baby finally managing to walk for the first time, they'll just erase it, getting more space for that zuzanna_big_t***.AVI / tax_return_done_quickly_no_malaware_cr3t1n$.docXXX file...

And that folks is the bitter truth. Our life data matter little. Our buying habits data, are sellable.

(morose music)

Someone should told hunter about data wiping. Oh wait he was trying to get it fixed ???