Software to securely overwrite unused disk space on PC hard drive?

[mattk1]

Hi guys,

I have had a search but can't seem to find anything suitable for my particular needs.

I want to securely overwrite the areas of my hard disk that I have recently deleted some personal files from so that I can sell my laptop without all the hassle of reformatting and updating it again, as it does already work excellently.

So what i'm after is some sort of zero writing facility that is smart enough to look for disk space that once contained data and then overwrite it making it irretrievable. I hope that makes sense

If such software exists it will make my life much easier to do that than to have to mess around completely reformatting and reinstalling everything..

Thanks in advance if anyone can direct me to a solution to this.

Kind regards,

Matt

[ThaidDown]

Suggest use of Eraser or CCleaner to erase free space. Can select one or more passes with various algorithms Up to 35 passes for the paranoid.

Eraser (old but good) http://eraser.heidi.ie/

CCleaner (select 'Tools' then Drive Wiper) https://www.piriform.com/ccleaner/download

Make sure you select 'wipe free space' and not wipe disc !!

[2008bangkok]

+1 for ccleaner

[Chao Lao Beach]

Maybe we can make a thread speculating on what you are wanting to hide !!!!!! Just kidding

[David48]

+1 for ccleaner

+2

Also what I have used.

It's in the 'Tools' -> Drive wiper

Just make sure that you have it set at 'Free Space Only'

[Tywais]

+1 for ccleaner

+2

+3

[mattk1]

Hey guys,

Thanks for all the replies with the suggestions of ccleaner, sounds like that is the one I need

To Chao Lao Beach; As for what I'm trying to hide, think of me naked wearing a santa hat and you'd be pretty close..

[Pib]

+1 for ccleaner

+2

Also what I have used.

It's in the 'Tools' -> Drive wiper

Just make sure that you have it set at 'Free Space Only'

And here's the CCleaner webpage link to the documentation regarding wiping free space. Link

[Lissos]

Suggest use of Eraser or CCleaner to erase free space.

I can vouch for Eraser. I haven't used it in years though. It may be best to get the latest version from SourceForge.

35 passes? If one wishes to wait about 3 days on an average free disk space erase, yes (tried once, never again).

I remember reading an article a few years back from someone clued up on this subject that for the average user who just wants to go over any traces of private documents or photos of themselves naked wearing a santa hat, an erase pass of 1 to 3 will be more than sufficient, with 1 pass even being enough. What the author of it was pointing out that beyond that level of erase, somebody would have to be really dedicated and equipped to want to dig so deep for material from an old drive that such a level of examination and dedication is Government and law enforcement based levels of scrutiny.

[aarn]

I also had a problem with myself pictured as naked santa (+ more), obviously very drunk.

Even though I took to the hard drive with a blow torch then a sledge hammer,

the neighbours 6 year old kids put it back together into two days and repeatedly emailed me

said pictures of self in red-capped natural glory.

This Xmas, rather than forego the santa wardrobe,

I plan to declare an electronic device-free zone. AA

[NeverSure]

+1 for ccleaner

+2

+3

+5 and it's free.

[Sayonarax]

Suggest use of Eraser or CCleaner to erase free space.

I can vouch for Eraser. I haven't used it in years though. It may be best to get the latest version from SourceForge.

35 passes? If one wishes to wait about 3 days on an average free disk space erase, yes (tried once, never again).

I remember reading an article a few years back from someone clued up on this subject that for the average user who just wants to go over any traces of private documents or photos of themselves naked wearing a santa hat, an erase pass of 1 to 3 will be more than sufficient, with 1 pass even being enough. What the author of it was pointing out that beyond that level of erase, somebody would have to be really dedicated and equipped to want to dig so deep for material from an old drive that such a level of examination and dedication is Government and law enforcement based levels of scrutiny.

The average image recovery program can recover old NTFS file structures further back then 1 pass wipe.

[Guest]

The question made me think how this should be done in the Linux/OSX operating systems. As the original question have been answered, this is what I came up to in case someone is interested. The script should fill the disk ten times with random data.

$ for i in `seq 1 10` ; do echo "Overwriting $i of 10 times" ; dd if=/dev/urandom of=$HOME/dump.tmp bs=4k; sync ; sleep 5 ; rm $HOME/dump.tmp ; sync ; sleep 5 ; done

[BKKdreaming]

"The average image recovery program can recover old NTFS file structures further back then 1 pass wipe. "

does it just write x and o over all the un-used hard drive ?

and if that is true why would it not do a good job the first pass ?

[bendejo]

One of the things I don't like about scrubbers is they leave an obvious pattern that someone investigating can easily determine the empty space has been scrubbed. Here's a recipe:

put together a large binary file, maybe a vid capture of a television feed, an old copy of google earth, anything really, so long as it doesn't contain any of your own data. Several files would be ok.

Using a defrag program, set to "defrag and optimize" (I suggest Auslogic's Disk Defrag). This will close up the gaps in your file system, so that all the free space on the partition will be one large area between the existing files and the end of the disk space. Now start copying those huge trash files over until the disk fills up. You'll have to give the file(s) a new name each time you copy it over, or create subdirectories. When the file system is full you can then delete the trash files.

Ok, this may be overkill. If you use something that puts zeroes (or any repeating pattern) it's obvious you scrubbed the disk, which will give the impression you have something to hide, which may inspire whoever is doing the examining to look further. The trash file method isn't so obvious and can offer a distraction "hey, we got something here!" and after hours of extracting the data they find themselves with a bunch of old Jeopardy! episodes. If you know someone will be snooping for personal correspondence put together some fun stuff for them, like a copy of the Magna Carta or the UN Charter saved as a Word doc.

[phazey]

The images were uploaded to the internet days ago, i'll post the links in a bit.

[adammike]

its normal to want to wipe a hard drive its necessary, its

about getting rid of passwords,banking details and of course those pics of that drunken night in a ladyboy bar etc etc,one guy from a data company said the only safe way

to erase a hard disc is to hammer a six inch nail through it,I left one in a bucket of water on my balcony for a few

months,if you really have stuff that could get you in jail

do not sell it remove it drill a few holes in it bury it.

[mattk1]

Hey guys,

Cheers for all the helpful replies, especially regarding CCleaner, that is a great piece of software and amazing that it's free. That being said, I will upgrade to the pro version as I think this is definitely software worth supporting.

As for how many passes I will use to clean the drive, I think one pass is enough as it's only old photos and some emails etc that I want to make difficult to recover should anyone use some recovery software when I sell my computer.

Great advice about the trash file overwrite idea though and i'll bear that one in mind in the future

Thanks guys.

Matt

[NeverSure]

One of the things I don't like about scrubbers is they leave an obvious pattern that someone investigating can easily determine the empty space has been scrubbed. Here's a recipe:

put together a large binary file, maybe a vid capture of a television feed, an old copy of google earth, anything really, so long as it doesn't contain any of your own data. Several files would be ok.

Using a defrag program, set to "defrag and optimize" (I suggest Auslogic's Disk Defrag). This will close up the gaps in your file system, so that all the free space on the partition will be one large area between the existing files and the end of the disk space. Now start copying those huge trash files over until the disk fills up. You'll have to give the file(s) a new name each time you copy it over, or create subdirectories. When the file system is full you can then delete the trash files.

Ok, this may be overkill. If you use something that puts zeroes (or any repeating pattern) it's obvious you scrubbed the disk, which will give the impression you have something to hide, which may inspire whoever is doing the examining to look further. The trash file method isn't so obvious and can offer a distraction "hey, we got something here!" and after hours of extracting the data they find themselves with a bunch of old Jeopardy! episodes. If you know someone will be snooping for personal correspondence put together some fun stuff for them, like a copy of the Magna Carta or the UN Charter saved as a Word doc.

I don't think that would work. Normal data doesn't fill every cluster. There's always a lot of blank space even on a "full" disk. I think the way to do it is to use a dedicated wiping program and do several overwrites. The 1 and 0 overwrites are random, not sequential.

Cheers

PS I still vote for CCleaner because it has several good functions and it's free.

Edited November 6, 2014 by NeverSure