Formatting before selling your PC

One of the most important things to do before selling your PC is to wipe all the Data in it. What most people do is just format the drive and sell it. This is not a safe practice and your Data would still be present on the Disk. When we click format the computer rewrites the partitions to be recognised as fully empty but all the data would still be there. The best thing to do is to use a partition tool and rewrite every bit of data with 0's and 1's so that your data is completely removed from the Drive. This will take some time but it is totally worth the time and is essential before selling your computer.

 

I agree. The last thing a person should ever do when selling it is to leave the original data on it or to where sensitive information is recoverable. I can't tell you how many times I've picked up a desktop or laptop from a pawnshop for use with a specialized purpose or even for parts for something big that I didn't have time to order, and found that all of the information was there, right down to cat pictures, photos of family, and document scans of info they'd never want anyone else to have. I'm not even going to tell you about some of the alarming porn pictures or other things I've seen just out of curiousity to wonder who owned it before I deleted it and used a system for parts. For a lot of reasons, both for their own and for the sake of who buys it, people should always clear off and clean off the old system before selling it as refurbished or selling it to a new owner.

 

Active KillDisk is a Powerful and compact piece of software that allows you to “destroy all data” on hard disks, USB drives and floppy disks completely, this could be handy if you are selling.

Just download the program, and after installation choose a platform to store the program to
these include, a cd drive, usb stick, or a floppy disk.

Once installed onto the other drive I.E. a usb stick you can then run the program on
any netbook, computer or laptop.

Here's a link,

http://www.killdisk.com/


You could also delete all of your personal files then use Ccleaner “to permanently erase” the free space, this free space is where the deleted files would be. Deleted files are recoverable.

Using Ccleaner goto the tools section then click on drive wiper.

 

Yes, just formatting will not do. It won't save your precious data from falling into the wrong hands. There are software like recuva that can bring back your deleted data.
Though there are various software which permanently deletes your data. A quick google search will give you lots of name. All are equally reliable.

 

I understand the importance of formatting the computer before selling it. If you don't format our computer, our data can be recovered by the buyer and our security can be breached or our data can be stolen. However, I did not know about the program that destroys all data. I will check the link and see if it is of any use to me.

 

NOTE:


Active kill disk will erase “everything” this includes your operating system files
it will take the hard drive back to “near enough” a new drive.

No system files nothing

 

Glad to come across this information! My brother has old laptop that he wanted to recycle but he was afraid to bring it in with whatever information left on it. I will pass this to him so he can do what necessary to clean out his information before recycling it.

 

I have software that will recover almost anything from any kind of a device or memory card. Although, I never thought about using it for sinister purposes, but in the wrong hands such software is really dangerous. I remember this guy who sold a laptop to my friend. The guy just deleted his stuff and even let my friend use his login information. I mean dude, if my friend was a thief, you'd be bankrupt.

So, this is great advice here. Always wipe the thing clean. Leave nothing to chance.

 

Formatting or deleting files does not actually delete or destroy files, it simply removes the access point to find or use the files. You need to overwrite the free space after you delete or format. A good multi-pass overwrite will make it so that files can not be recovered. There are a multitude of free programs that can overwrite with a format or overwrite the free space if you just delete personal information or files.

 

There are people that even go further then that, they actually will sell the computer with out a drive. There are boxes that you can place the drive into and use it as an external drive.

 

Now that is just paranoia. A proper overwrite would keep even the NSA from gathering your old files.

 

Not always. I probaby shouldn't say this here, but on some drives there are what you might call a restricted area (outside writeable sectors and tracks on the drive).

The DoD and DoD Short (3, 5, and 7 pass) methods will keep most people out, and Peter G's method with 35 passes will even more so when combined with a random overwrite...but the problem is that if they really want the data back, the NSA does have a type of electron-scanning microscope capable of reading the history of changes made to the filings of magnetic drives, and it doesn't end there. Not to say that the methods used aren't thorough to obfuscate it, because they are...but the dilemma remains for users when data security and anonymity are no longer analyzed at the consumer and corporate levels and are passed on into the domain of government.

Beyond the normal (older) methods of using an electron scope to manually try and read back X amount of times to recover data by how the analyst would see portions form on the drive, there is now a device (since the late 90's) and an algorithm used together which determine the way the filings were moved in either direction to be a 1 or 0 on the drive recursively, even if the electron microscope cannot or may be yielding a false-positive.

The prediction algorithm uses density and formulas based on previous data (whether recoverable or not) to make a prediction on whether or not the last successive write made to that portion of the drive was a 1 or a 0. It can be told how many times to do that to an area of a drive or by a gradual length until recognized data (like common header data in executables, mp3s, and image formats) are detected and become readable. Once that happens, they know how many times the data has been overwritten by. They can then determine from there if individual files were overwritten or deleted by files or directories at a time, instead of it being done to the whole drive.

At this point as well, the drive data that is readable is usually cloned or copied in part onto a dupicate medium, maintaining any readable or recognized time and date stamp if available from the file system. If there is no file system, the data is copied as-is to preserve as much as possible, because even though it's rare, it's still possible for a filing to become depolarized to the point that recovery of one or more nibbles or bytes have to be guessed from 16 to 256 possible combinations, or worse, if it has to be done a bit at a time and filings no longer hold a trace of either value before.

The data that is normal and readable on a drive gets isolated, copied, and/or ignored but the data which may have been deleted or the same method used partially, gets the focus for extended recovery at that point. This part is something that could be done outside of the lab as it usually just involves recovering and reconstructing the original data from the free space area at that point, and pointing it back to its name and doing a CRC check on it if using an NTFS stream, FAT, linux/EXT filesystem, or something else based on what was found.

That's just the magnetic drives. The SSDs have twice the data storage space as they report, but are using compression-per-cell to store an extra 30% on the drive over the 50% that exists but is not reported as useable to the controller. It is marked as a "bad cell", even though it's perfectly fine. Recovery data for deleted files starts filling up the "unused" area of some SSD drives so in the event that a user thinks they have securely deleted or erased a flash drive, MMC, or SSD drive...recovery of some or all of it is often still possible without the user realizing it because of what the manufacturer has hidden in storage capacity on behalf of the government and other organizations who might want or need to recover data without you realizing it later on.

So if you're selling it to someone who won't realize this or use or have access to any of these tools or resources, then you're probably ok. If you're not sure who you're selling it to and they do work for government or military computer science in research, development, or anything else...you're not being paranoid at that point, and you most asuredly do want to remove the drive and replace it with an empty one if you are an inventor, researcher, developer, or holder of any type of information, such as for another country, that may not be safe to release or know regardless how thorough the method initially was.

Oh, and if you want a free alternative to using Active KillDisk that works as a linux live CD and does the same things that it does completely, check out a tool called Parted Magic 2013. There's updates to it since, but the 2013 version was the last freeware one, and should still be available for anyone here to use without any restrictions.

 

A very extensive article on the subject thanks

 

@IBMPC8088 very good post. Most people don't have such important information on that computer that could warrant the cost involved to recover that data. I can see that being used for espionage. Looks like it doesn't matter what you try to do there will always be trace information on your drive.
Looks like the idea of staying with your drive before you sell your computer is looking better and better.

 

That's a very informative post. I honestly would never think of that, as I always thought formatting a drive would delete everything inside it. I don't plan on selling my PC, but in the future I might give it to my siblings, so I guess I can use this trick when I am giving it to them, so they'll have a brand new CPU without any data in it. I'm sure they would appreciate it too, as I have taken care of my PC very well for the years that I have had it, and I am proud to say that it still works in wonderful condition.

 

@OursIsTheFury Yep. An overwrite is your friend. Just remember that and it will be fine.

 

Always a good reminder. I have a few computers that I just won't sell because I am so worried that my info will be left on it somehow. Passwords, pictures, documents, etc. I actually bought my current laptop from a friend and they said that they wiped it, which really meant they put everything in the "Recycle Bin". The amount of porn, nudes, and other disturbing images that I found was enough for me to wipe the entire thing. I just sent them an email (since that was still pulled up) and said "Your pictures have been destroyed. Nobody will ever know your secret lifestyle, you party animals." They were embarrassed, but I assured them that I didn't do anything except make that permanent delete possible. A little computer education goes a long way.

 

Deleting the files didn't get rid of them. You would have needed to format the drive and overwrite it. If the prior email software was available to you and still up you clearly didn't do this.

 

In 2009, when we bought this present desktop, a neighbor offered to buy the old one. And since there is no more use for us, we gave it to her for peanuts. But my husband had to erase the hard disk. Yes, he formatted the hard disk so it will feel like new (to the buyer). But if you say that the data would still be there and can be recovered, I guess that's our fault. Fortunately, the neighbor is a newbie and I'm sure she has no use for our data so there would be no intention to recover.

But this is a good food for thought not only for selling old computers but also for selling used hard disk.

 

Just make sure that an overwrite is done in addition to a format if you do this in the future and it will be fine. As your neighbor uses that old system the files he uses and saves will gradually overwrite your old data. If she isn't tech savvy or interested she isn't going to uncover your old info if a format was done.