How To Permanently Erase Deleted Files

[junkofdavid2]

Hi,

I'm selling my 2 old PCs with Windows XP (fake copies I think... installed in IT City. I used to have original but can't find the CD bought by old manager).

Anyway, I have to delete some private files but not all of them because the buyer wants the PCs for some of the information on it (so re-formatting is out of the question).

How do I permanently erase deleted files without risking deleting the current files?

Can anyone recommend a free CNET program which is good and will erase deleted files completely, without harming the existing files?

What steps do I take to make sure that the existing files aren't harmed by the erasure of the deleted files?

(My biggest fear is that I'm not a tech dude so I might erase the wrong files...)

Cheers,

Mike

Edited July 6, 2007 by junkofdavid2

[FormasianPaul]

Hi,

I'm selling my 2 old PCs with Windows XP (fake copies I think... installed in IT City. I used to have original but can't find the CD bought by old manager).

Anyway, I have to delete some private files but not all of them because the buyer wants the PCs for some of the information on it (so re-formatting is out of the question).

How do I permanently erase deleted files without risking deleting the current files?

Can anyone recommend a free CNET program which is good and will erase deleted files completely, without harming the existing files?

What steps do I take to make sure that the existing files aren't harmed by the erasure of the deleted files?

(My biggest fear is that I'm not a tech dude so I might erase the wrong files...)

Cheers,

Mike

http://www.snapfiles.com/download/dlezwipe.html

"EZ Wipe integrates with the Windows Explorer right-click menu and allows you to securely delete selected files by using a 3-pass or 7-pass overwrite model that prevents recovery of the delete files with common undelete tools. Simply right-click on a file and select the `EZ Wipe` option from the menu.

This is a FREEWARE option

There are loads of buyware out there, but I have used this with no problems

The big question is... what you trying to hide

[Tywais]

Another free version > Eraser

[cdnvic]

http://www.heidi.ie/eraser

Been around for ages, and proven.

If you want better security, you'd have to grind the drives to powder.

[sibeymai]

I'd be cautious of any software which prevents the recovery of these files through the Windows operating system.

What if EZ Wipe is removed ? Can the files then subsequently be recovered ?

Removal through a software tool may leave the file physically on the disk which can then be recovered through a number of software tools.

If you really want the files to be removed you need a software tool which will physically erase the sectors of the disk where the file was store.

Perhaps the easiest way may be to substitute the contents of the file with meaningless data. I think the operating system will attempt to rewrite the file to the same disk sectors where it is already stored. If this is correct (someone may be able to verify this), then by writing a slightly larger file than the original should overwrite all the previous data on the disk.

[FormasianPaul]

I'd be cautious of any software which prevents the recovery of these files through the Windows operating system.

What if EZ Wipe is removed ? Can the files then subsequently be recovered ?

Removal through a software tool may leave the file physically on the disk which can then be recovered through a number of software tools.

If you really want the files to be removed you need a software tool which will physically erase the sectors of the disk where the file was store.

Perhaps the easiest way may be to substitute the contents of the file with meaningless data. I think the operating system will attempt to rewrite the file to the same disk sectors where it is already stored. If this is correct (someone may be able to verify this), then by writing a slightly larger file than the original should overwrite all the previous data on the disk.

I would be cautious too if the files being deleted were system files and programme files, but I made the assumption (perhaps wrongly?!?) that the files being personal were document files rather than programme files.

If you are looking at removing programme and system files then try : http://www.revouninstaller.com/ (again FREEWARE).

If you are that worried about handing over a machine that doesn't work after removing any files, you may want to consider backing it up completely first, then deleting what you need. If there are any problems after you have deleted something you can perform a full system restore (DONT use the System Restore Tool built into MS XP - this will cause you more problems!)

[junkofdavid2]

Basically I'm removing DATA FILES (pictures and stuff ) , but

I'd also like to remove Program Files only of my InterbankFX forex account and make sure that my passwords are erased from the system.

Is EZ Wipe or Heidi kinda safe to use so that I can choose the files to be deleted? (I don't want to unintentionally delete files or programs which need to remain).

How to do?

Edited July 6, 2007 by junkofdavid2

[A_Traveller]

Eraser is a file {or directory} deletion program which then overwrites x number of times the hard disk space which the deleted file occupied. It also adds an erase option to the Recycle Bin, so one could delete as per Windows, and then Erase the recycle bin 'contents'. When one deletes all one does is change the file name to tell the OS the file is deleted and the space is free, which is how file recovery works.

After you have deleted and or erased and then if required removed any program using uninstall or Add/Remove Programs in Control Panel, Eraser can also be run on all free space thereby making recovery of any data or programs held on the system unlikely.

Regards

[Rice_King]

Basically I'm removing DATA FILES (pictures and stuff ) , but

I'd also like to remove Program Files only of my InterbankFX forex account and make sure that my passwords are erased from the system.

Is EZ Wipe or Heidi kinda safe to use so that I can choose the files to be deleted? (I don't want to unintentionally delete files or programs which need to remain).

How to do?

Why not use one of the aforementioned utilities and wipe the COMPLETE disk, then reinstall the OS (if you want) prior to sale?

[Bizz]

This might shed some light on your problem

National Cyber Alert System

Cyber Security Tip ST05-011 archive

Effectively Erasing Files

Before selling or discarding an old computer, or throwing away a disk or CD, you naturally make sure that you've copied all of the files you need. You've probably also attempted to delete your personal files so that other people aren't able to access them. However, unless you have taken the proper steps to make sure the hard drive, disk, or CD is erased, people may still be able to resurrect those files.

Where do deleted files go?

When you delete a file, depending on your operating system and your settings, it may be transferred to your trash or recycle bin. This "holding area" essentially protects you from yourself—if you accidentally delete a file, you can easily restore it. However, you may have experienced the panic that results from emptying the trash bin prematurely or having a file seem to disappear on its own. The good news is that even though it may be difficult to locate, the file is probably still somewhere on your machine. The bad news is that even though you think you've deleted a file, an attacker or other unauthorized person may be able to retrieve it.

What are the risks?

Think of the information you have saved on your computer. Is there banking or credit card account information? Tax returns? Passwords? Medical or other personal data? Personal photos? Sensitive corporate information? How much would someone be able to find out about you or your company by looking through your computer files?

Depending on what kind of information an attacker can find, he or she may be able to use it maliciously. You may become a victim of identity theft. Another possibility is that the information could be used in a social engineering attack. Attackers may use information they find about you or an organization you're affiliated with to appear to be legitimate and gain access to sensitive data (see Avoiding Social Engineering and Phishing Attacks for more information).

Can you erase files by reformatting?

Reformatting your hard drive or CD may superficially delete the files, but the information is still buried somewhere. Unless those areas of the disk are effectively overwritten with new content, it is still possible that knowledgeable attackers may be able to access the information.

How can you be sure that your information is completely erased?

Some people use extreme measures to make sure their information is destroyed, but these measures can be dangerous and may not be completely successful. Your best option is to investigate software programs and hardware devices that claim to erase your hard drive or CD. Even so, these programs and devices have varying levels of effectiveness. When choosing a software program to perform this task, look for the following characteristics:

* data is written multiple times - It is important to make sure that not only is the information erased, but new data is written over it. By adding multiple layers of data, the program makes it difficult for an attacker to "peel away" the new layer. Three to seven passes is fairly standard and should be sufficient.

* use of random data - Using random data instead of easily identifiable patterns makes it harder for attackers to determine the pattern and discover the original information underneath.

* use of zeros in the final layer - Regardless of how many times the program overwrites the data, look for programs that use all zeros in the last layer. This adds an additional level of security.

While many of these programs assume that you want to erase an entire disk, there are programs that give you the option to erase and overwrite individual files.

An effective way to ruin a CD or DVD is to wrap it in a paper towel and shatter it. However, there are also hardware devices that erase CDs or DVDs by destroying their surface. Some of these devices actually shred the media itself, while others puncture the writable surface with a pattern of holes. If you decide to use one of these devices, compare the various features and prices to determine which option best suits your needs.

[Tywais]

An effective way to ruin a CD or DVD is to wrap it in a paper towel and shatter it.

Even better and easier way, stick it in the microwave for about 10 seconds. You end up with a nice clear piece of plastic.

[Bizz]

Address to above

Mod please look at url before deliteing

http://www.us-cert.gov/cas/tips/ST05-011.html

[cdnvic]

Unless you are selling it to the CIA or something, doing more than running Eraser over it is a bit over the top.

[junkofdavid2]

I have eraser now...

but I can't seem to know how to "select" the files to be erased.

(I just want to erase the files in my recycle bin).

There's a step by step instruction guide but it doesn't say "how to select" the file to be erased.

Step 1: how to choose interface

step 2: select preferences

step 3: choose method

step 4: Now that you have chosen method, select the files to be erased and then click run"

huh? am i missing something? how do i select the files???

I might end up erasing everything!!1

[cdnvic]

I have eraser now...

but I can't seem to know how to "select" the files to be erased.

(I just want to erase the files in my recycle bin).

There's a step by step instruction guide but it doesn't say "how to select" the file to be erased.

Step 1: how to choose interface

step 2: select preferences

step 3: choose method

step 4: Now that you have chosen method, select the files to be erased and then click run"

huh? am i missing something? how do i select the files???

I might end up erasing everything!!1

Right-click on the files in Windows Explorer and choose 'Erase'

[A_Traveller]

Alternatively, delete the files as normal in Windows. Then right-click on the Recycle Bin and the additional option is available to erase recycle bin. Click there and the process will continue.

Regards

[britmaveric]

disk ko - 5x sweeps is standard security protocol to make a hd unrecoverable for past data

[junkofdavid2]

I'm using the Heidi Eraser now and it seems to work fine.

I'm not selling to the CIA or anything, and nothing criminally incriminating for me... so I opted for the "Pseudorandom Data" option... which is the quickest and is only a one pass overwrite.

(can choose 1-pass pseudorandom, 3-pass, 7-pass, and 35-pass which will take forever)

1) What does "pseudorandom" mean in this case?

2) There is another option called "only the first and last 2KB". How does that "protect" a deleted file?

[A_Traveller]

I'm using the Heidi Eraser now and it seems to work fine.

I'm not selling to the CIA or anything, and nothing criminally incriminating for me... so I opted for the "Pseudorandom Data" option... which is the quickest and is only a one pass overwrite. [More passes are better]

(can choose 1-pass pseudorandom, 3-pass, 7-pass, and 35-pass which will take forever)

1) What does "pseudorandom" mean in this case? [simply that a code arithmetically generates a sequence which displays randomness]

2) There is another option called "only the first and last 2KB". How does that "protect" a deleted file? [breaks the chain between blocks, a quick option for a busy drive. ie. raided photo storage]

Regards

[cdnvic]

1) What does "pseudorandom" mean in this case?

It's just writing random data over the file. similar to if you had installed a program over top of it.

2) There is another option called "only the first and last 2KB". How does that "protect" a deleted file?

That will be the "organizing" data that tells the system how to read it. Without it the file is pretty much dead.

I'd compromise and do a 7 pass erasure overnight.

Edited July 7, 2007 by cdnvic

[junkofdavid2]

How do I erase usernames and passwords for things like my MSN messenger and Yahoo Messenger?

I can't find the file.

Is it enough to uninstall them?

Edited July 7, 2007 by junkofdavid2

[cdnvic]

How do I erase usernames and passwords for things like my MSN messenger and Yahoo Messenger?

I can't find the file.

Is it enough to uninstall them?

They are stored in cookies (msn and yahoo web logins) and profiles (should delete on uninstall).

The fastest and least complicated way to use eraser is to just delete the files all with Windows (Hit shift+del to bypass recycle bin and permanently delete) and then let Eraser work overnight with "wipe free space" selected.

Edited July 7, 2007 by cdnvic

[junkofdavid2]

which would be more effective?

The pseudorandom option or the "only first and last 2KB" option?

And which one is expected to be faster?

[cdnvic]

which would be more effective?

The pseudorandom option or the "only first and last 2KB" option?

And which one is expected to be faster?

If those were my choices I'd take the first and last 2kb. No idea which is faster.

[A_Traveller]

Why not just delete to Recycle Bin and then run pseudorandom 7 passes overnight?

Regards

[junkofdavid2]

It'd take forever.

We're talking about 100 GB here...

[A_Traveller]

It'd take forever.

We're talking about 100 GB here...

From experience, if you didn't run cluster tips {which on the basis of your description you don't need} then I'd expect a run as I 'speced' to take about 18 hours.

Regards

/edit clarification//

Edited July 7, 2007 by A_Traveller

[britmaveric]

Take security of your data over time - well unless you want your data compromised.