Would you buy a second hand laptop computer ?

[MuzzerParticipant @muzzer]

You can get yourself a nice 2.5" SSD and a "pre-used" copy of Windows 7 or 10 for £50 or so all in. Often this will transform an old clunky machine into something really quite usable. I did this with a Lenovo my mother had given up on and it's given me a couple of years of good service ever since. Good for streaming music from the NAS to the workshop hifi, surfing for datasheets etc and bits of CAD work in the workshop – or as an emergency backup in the house.

Having said that, a second hand laptop has very little commercial value unless almost new and will become obsolete quite rapidly, so coughing up another £100 or so for a new one with warranty may be sensible depending how computer savvy you are.

Murray

[mgnbukParticipant @mgnbuk]

When my wife's Medion died, we looked into various options & ended up with a second hand Dell from a local independant computer shop. The going rate at the time for a new i3 HP with a 768 display was £399 – the Dell was an i5 with a 1080 display for £50 less. Both came with W10 Home & 12 months warranty. The used machine has been problem free for the last 12 months. IIRC the shop said that the used Dells he sold came direct from Dell.

At work my workstation is a used HP that came from Pyramid Computers. W7 Pro & problem free for the last 3 years. IIRC it was £200-ish & came next day.

Seem to be able to get better performance for less money buying an ex-commercial machine & I will look in that direction first next time I need one.

Nigel B

[Russell EberhardtParticipant @russelleberhardt48058]

Windows 10 is possibly a bit much for a five year old laptop. Why not dig it out of the cupboard and install a lightweight edition of Linux on it instead? You might be surprised at the performance.

Russell

[vintagengineerParticipant @vintagengineer]

Do not buy one unless you can trust the previous owners. You will never know what has been down loaded. If you do buy make sure you keep the receipt as proof of date of ownership. That way you can prove what files you are liable for.

And remember you can never delete files from the hard drive, you need to remove the hard drive and smash it with a large hammer. This is the only way to stop anyone retrieving any data from the drive!

[Russell EberhardtParticipant @russelleberhardt48058]

Posted by vintagengineer on 19/08/2017 21:47:54:

And remember you can never delete files from the hard drive, you need to remove the hard drive and smash it with a large hammer. This is the only way to stop anyone retrieving any data from the drive!

This is overkill. While just deleting files will not get rid of them entirely, there are plenty of programs available that will wipe the disk and overwrite any existing files. I've used Bleachbit. If you just install Linux in place of Windows the installer will reformat the disk in EXT4 rather than FAT format and any remaining files will become unreadable.

Russell

[vintagengineerParticipant @vintagengineer]

Having worked for a major bank on IT security we found this was the only way to be 100% sure that all data was rendered un-useable. We never sold or disposed of any hard drives without destroying them. We were advised by Government security advisors that you can always recover data from a hard drive and it was proven to us that this was possible.

Posted by Russell Eberhardt on 20/08/2017 10:32:10:

Posted by vintagengineer on 19/08/2017 21:47:54:

And remember you can never delete files from the hard drive, you need to remove the hard drive and smash it with a large hammer. This is the only way to stop anyone retrieving any data from the drive!

This is overkill. While just deleting files will not get rid of them entirely, there are plenty of programs available that will wipe the disk and overwrite any existing files. I've used Bleachbit. If you just install Linux in place of Windows the installer will reformat the disk in EXT4 rather than FAT format and any remaining files will become unreadable.

Russell

[SillyOldDufferModerator @sillyoldduffer]

Posted by Russell Eberhardt on 20/08/2017 10:32:10:

Posted by vintagengineer on 19/08/2017 21:47:54:

And remember you can never delete files from the hard drive, you need to remove the hard drive and smash it with a large hammer. This is the only way to stop anyone retrieving any data from the drive!

This is overkill. While just deleting files will not get rid of them entirely, there are plenty of programs available that will wipe the disk and overwrite any existing files. I've used Bleachbit. If you just install Linux in place of Windows the installer will reformat the disk in EXT4 rather than FAT format and any remaining files will become unreadable.

Russell

 

Sorry to disagree Russell. Much depends on how badly someone wants to read that disk. Time, money and inclination.

1. Deleting a file just removes the file's name from an index and frees the storage so it can be used by something else. The data is unchanged until it's actually overwritten. Large portions of the original data may remain intact and retrievable, possibly for years. Even if if the storage is reused, see point 5 below!
2. Repartitioning a disk completely destroys the operating systems understanding of how folders and files were organised but the data is still intact and can be retrieved. Not easily, but certainly possible.
3. Reformatting a disk is more brutal, but even that does not necessarily touch old user data. For example MSWindows Quick Format is superficial. Full format is more likely to damage data structure, but it is still possible to retrieve data. It may be hard work to piece it together, but it can be done.
4. The real killer though relates to the way hard-drives work. They are analogue devices. Being mechanical, a disk's read/write head does not accurately position over the track each time it passes. That means readable old data can be recovered from an overwritten track by careful positioning of the read head. Recovering data this way is costly. It may require the disk platter to be removed and mounted in another machine, and post-processing of multiple possibilities. But it can be and is done.

The range of recovery options can be very useful. If important data is accidentally deleted, there's a reasonable chance of getting it back. There are companies specialising in this kind of work, but be warned – they're not cheap.

From a security point of view, smashing the disk will usually put the data beyond economic recovery. Even then, be aware that 'military grade' destruction requires disks to be physically smashed and incinerated. That's because, in theory, a well-funded government agency could still to get data off the bits.

Software methods of erasing disks have a cheesy reputation in the trade. Various reasons such as for efficiency, most operating systems and disk controllers are unwilling to write data to physical media unless they really, really have to, preferring to wait until it's convenient to them. That means it's possible for a higher level program to think it's comprehensively overwriting a disk when in fact it's only pointlessly overwriting buffers in memory. The way software methods depend on implementation detail isn't strong security. It might work well on one system build and badly on another.

As it's so easy to do, I always smash old disks before disposal. One good whack with a small hammer is enough.

Dave

Edits, typos galore!

Edited By SillyOldDuffer on 20/08/2017 11:49:48

Edited By SillyOldDuffer on 20/08/2017 11:51:11

[SandgrounderParticipant @sandgrounder]

Are we not talking about two completely different levels of security requirements here? Obviously organisations like Banks, the NHS, Police etc must do the ultimate to prevent loss of data, but for the average person is it necessary? If I sold my PC after just deleting the files, is it likely that the new owner is going to go to the trouble of finding some special software or whatever is required to search the hard disc, to be honest if I sold it on without deleting anything the new owner would soon get bored looking at old holiday photos and reading my emails etc, even my bank account numbers are passed on when I use my card or write a cheque so they aren't that secret.

If some dishonest person thought that my PC would contain very desirable info' he would probably break into my house and steal the PC, not wait until I sold it.

John

[jaCK HobsonParticipant @jackhobson50760]

Recovering _some_ data from a disk of deleted files is trivial for some people. Recovering data from a securely wiped disk is not. Putting a nail through the disk platter would probably put a foreign intelligence service off the idea of recovery. For my home PCs I wouldn't care about the data on there but a bash with a hammer is easy. For work, secure shredding.

Second hand laptops – I wouldn't bother but if I got one I think I'd want to put a new disk in. Borrowed USBs = no. Freebie marketing USBs = no. First sign of any virus – reinstall the OS i.e don't bother to patch.

New Laptop – I prefer to reinstall the OS to get rid of bloat but not always.

[RJWParticipant @rjw]

Surely all the issues about security regarding hard drives is the concern of the seller of a PC, not the buyer as in the OP's case?
The easy option regarding security if selling a PC or laptop on is do what I do, keep the original drive and use it for storage, all your old stuff is still on there and can be transferred to a new PC using a caddy or USB jump lead, then stick a new one in the PC being sold and shove a fresh OS install on it, HD's are so dirt cheap now – even SD's, that it's hardly worth worrying about data breaches by leaving the old one in place.

John.

[Ady1Participant @ady1]

Whatever you get try and get a quad core version and plenty of RAM would be my only advice

(There's so much choice out there)

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, well I have had three second hand laptops, not for some years now, but I never had any issues with them. All I ever did was to wipe them with the free Killdisk that was available off the net, you could buy more effective ones, but I never found the need too, and then I reinstalled the OS. John, not so economical to replace the hard drive these days, as you would need to buy a new OS licence also, which would probably be as much if not more than you could sell the laptop on for. Second hand laptops are becoming so numerous, that they are hardily worth bothering spending any money on them to get a sale, as new laptops outsell desktop computers by a long way and the price of the more every day ones are quite low priced these days.

Regards Nick.

[RJWParticipant @rjw]

Posted by Nicholas Farr on 20/08/2017 13:52:51:

"John, not so economical to replace the hard drive these days, as you would need to buy a new OS licence also, which would probably be as much if not more than you could sell the laptop on for."

Regards Nick.

Nick, no need to buy a new installation key, all laptops these days have generally come from one of the big box movers and possibly tower units too unless it was a bespoke build, they will have had the OS pre-installed from new, the key is on a label on the base of the body and also embedded into the BIOS, you can generally use any installation disk from one of the big names too as long as it's higher than or equal to the format being replaced, I've frequently used Dell installation disks (tenner posted via a well known auction site) on all of my laptops including Toshiba, Acer and my Vaio, you may get asked to call Microsoft to verify the installation key, but it's an automated process and I've never had a problem with it.

John.

[MuzzerParticipant @muzzer]

+1 for used install disks – or in fact just the key these days (no actual disk required). And when you install it on a brand new SSD in place of the original HDD, you don't need to waste armchair time fretting about the security of a used disk.

W7 and W10 actually work well on relatively old machines. They seem to be lighter and more nimble than previous versions.

Murray

[SillyOldDufferModerator @sillyoldduffer]

Posted by Sandgrounder on 20/08/2017 12:11:29:

Are we not talking about two completely different levels of security requirements here? Obviously organisations like Banks, the NHS, Police etc must do the ultimate to prevent loss of data, but for the average person is it necessary? If I sold my PC after just deleting the files, is it likely that the new owner is going to go to the trouble of finding some special software or whatever is required to search the hard disc, to be honest if I sold it on without deleting anything the new owner would soon get bored looking at old holiday photos and reading my emails etc, even my bank account numbers are passed on when I use my card or write a cheque so they aren't that secret.

If some dishonest person thought that my PC would contain very desirable info' he would probably break into my house and steal the PC, not wait until I sold it.

John

One big concern is identity theft. Impersonation is much easier if the bad guy has access to a few personal details. Expect havoc if he knows your name, address, account numbers, interests, family details, web history, sources of income, service provider details and recent spending etc. Unless your computer is used for a narrow technical purpose, it will be a rich source of personal data. Small details add verisimilitude to confidence tricks. If they know enough, identity theft can be total.

Quite a few celebrity examples on the web (Gloria Hunniford has been done over twice), but most ordinary citizens are good for a few thousands. Even if you don't lose much cash, re-establishing your identity will be painful. You have to prove who you are after multiple institutions have been warned you're a fraud.

It's a mistake to assume 'no-one is interested in little me' especially where computers are involved. Big profits are made by attacking many soft targets. Do thugs go for Fort Knox or is it easier to take a few quid off little old ladies on pension day?

But yes, the point about different levels of security is well made. But don't underestimate the value of what's on your computer.

Dave

[Russell EberhardtParticipant @russelleberhardt48058]

Well, if you're a terrorist or suchlike perhaps you should smash your old disk but if you are only concerned about the possibility of malware being hidden on the disk of a second hand machine smashing the disk is ridiculous. Are MI5 going to come along and tear your computer apart and try to read hidden information?

Russell

[Ady1Participant @ady1]

Some folk are pretty paranoid and believe all the hype while others are lackadaisical about the risks

The easy answer is just do what you are happy with

Edited By Ady1 on 21/08/2017 09:53:36

[Neil WyattModerator @neilwyatt]

If you are an intelligence you can use special techniques to recover data. A bit written as a 1 will have a slightly different analogue value if it was previously a 0 or a 1. In fact it will have a different value if its history was 100, 101, 110 or 111. It may even go back further than that and be detectable.

I imagine it is highly unlikely that the effort of decoding a drive in this way, given that the error rate must be quite high, is useful of anything other than attempting to recover bulk text and looking for key words and phrases etc.

[Brian JohnParticipant @brianjohn93961]

I have decided to buy a new computer but nobody is doing any good deals on new laptops in Cairns at the moment so I will have to take what I can get. JB HIFI have two HP laptops. Both run Windows 10 : the 14'' costs $500 and has 4GB RAM, 1TB HDD and a 2.0 GHZ processor. The 15'' costs $600 and has 8GB RAM, 1TB HDD and a 2.5 GHZ processor. I spent an hour in the store today doing various things and the larger 15'' is definitely faster. I wanted a 14'' screen but I will have to go with the larger and faster computer.

Neither computer has a DVD reader/burner so I will have to buy an external device.

Edited By Brian John on 21/08/2017 10:20:31

Edited By Brian John on 21/08/2017 10:21:48

[SillyOldDufferModerator @sillyoldduffer]

Posted by Russell Eberhardt on 21/08/2017 09:38:11:

Well, if you're a terrorist or suchlike perhaps you should smash your old disk but if you are only concerned about the possibility of malware being hidden on the disk of a second hand machine smashing the disk is ridiculous. Are MI5 going to come along and tear your computer apart and try to read hidden information?

Russell

What to do if you buy a secondhand computer is one thing, disposing of it is an entirely different problem.

If I take on a secondhand computer, I reformat the disks and install a new operating system. That I think is sufficient to deal with any malware on the machine.

Safely disposing of an unencrypted computer is a much bigger problem. My personal data is valuable and so is yours! The easiest way of guaranteeing it's safety is to smash the disk.

Not very likely that MI5 are interested in me. Criminals might be. Don't forget that the 'criminal' might be a spotty kid who knows far more about computers than you do and enjoys technical puzzle solving. Earlier in the thread, someone mentioned buying a laptop containing material identifying the previous owner as the Halifax Bank. A deep look at the data on that machine might be very worthwhile.

However, the organisations most likely to have a serious go at your data are the police and/or tax authorities. An ex-colleague, and I would never have guessed what he was up to, is currently serving a well deserved prison sentence based on evidence recovered from his hard drive . Most of the data that got him banged up had been deleted.

Dave

[VicParticipant @vic]

I always thought that seven writes was enough to erase data on a HD?

**LINK**

I think I read somewhere that even the CIA considered this enough if a HD couldn't for some reason be physically destroyed.

[Ady1Participant @ady1]

You can wipe a disk clean to a bunch of zeros and 1's but it needs to be done sector by sector and it takes ages

Far more cost effective to trash it, chucking it into a furnace for example

Edited By Ady1 on 21/08/2017 11:28:23

[John CoatesParticipant @johncoates48577]

Posted by Chris Evans 6 on 18/08/2017 07:47:15:

I bought a new laptop about 5 years ago with windows 8 …….. Relegated it to a cupboard and bought a Lenovo Ideapad for about £150.

Younger than my 2009 HP Pavilion running Linux so if you want to dispose of your 5 year old laptop I'll take it off your hands Chris

[John CoatesParticipant @johncoates48577]

Posted by Ady1 on 21/08/2017 11:26:45:

Far more cost effective to trash it, chucking it into a furnace for example

Hopefully not the whole laptop Ady!

Waste electronic equipment is the fastest growing problem for those of us in the industry. The replacement life cycle of modern consumer electronics is frightening given that they utilise most of the world's scarcest metals which will not be replenished once they are all built into equipment, either ones in use or redundant ones in landfills

So folks please think about the reuse or recycling options before you get rid of your unwanted electronic equipment. As previously discussed laptops that can't run the latest version of Windows will perform very happily running Linux. Community groups know this and can take unwanted laptops and install Linux and give some deserving person a fully functioning laptop that (to Micro$hafts displeasure) can do everything a normal human being needs just without Windows

[Clive IndiaParticipant @cliveindia]

Posted by Russell Eberhardt on 20/08/2017 10:32:10:

Posted by vintagengineer on 19/08/2017 21:47:54:And remember you can never delete files from the hard drive, you need to remove the hard drive and smash it with a large hammer. This is the only way to stop anyone retrieving any data from the drive!

This is overkill. While just deleting files will not get rid of them entirely, there are plenty of programs available that will wipe the disk and overwrite any existing files. I've used Bleachbit. If you just install Linux in place of Windows the installer will reformat the disk in EXT4 rather than FAT format and any remaining files will become unreadable. Russell

It might be overkill – but the pleasure derived from doing it just cannot be measured!

[Author]

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