How to really erase old files in my laptop?

[yungman]

Hi

I want to give my older 4th gen I5 with windows 10pro to my granddaughter to use, but I have important files that I want to delete PERMANENTLY from the computer. I already deleted into the recycle bin. Then I clear the recycle bin already. What other steps I have to do to ensure the files are really deleted and nobody else can recover them?

Thanks

 

[jedishrfu]

There are disk writing software products that will write, erase, and rewrite every track several times with random data.

https://helpdeskgeek.com/free-tools-review/5-free-programs-to-completely-wipe-a-hard-drive/

Another strategy would be to simple remove the drive from the laptop and replace with a new one that doesn’t have your data. In that way, if the laptop was ever lost or stolen you wouldn’t worry about someone deciphering the disk looking for your data.

 

[yungman]

There are disk writing software products that will write, erase, and rewrite every track several times with random data.

https://helpdeskgeek.com/free-tools-review/5-free-programs-to-completely-wipe-a-hard-drive/

Another strategy would be to simply remove the drive from the laptop and replace with a new one that doesn’t have your data. In that way, if the laptop was ever lost or stolen you wouldn’t worry about someone deciphering the disk looking for your data.

Do they have free software or you have to buy it? Can I use a big file and just keep copying over and over to occupy the memory space?

I don't want to remove the disk as it has a lot of programs useful installed already, just want to erase the data files.

Thanks

 

[yungman]

There are disk writing software products that will write, erase, and rewrite every track several times with random data.

https://helpdeskgeek.com/free-tools-review/5-free-programs-to-completely-wipe-a-hard-drive/

Another strategy would be to simple remove the drive from the laptop and replace with a new one that doesn’t have your data. In that way, if the laptop was ever lost or stolen you wouldn’t worry about someone deciphering the disk looking for your data.

I am loading the Boot disk you suggested me to hack the computer last time for the password, it's 2.7G, so if I copy a few times, I can fill up the disk, you think that will do it?

 

[jedishrfu]

No it needs to be different data each time you do it. Writing the same data over and over is predictable and may be possible to recover your data knowing the pattern.

Also these program write at the track level not at the filesystem level to insure all traces are removed.

Use google to get a better understanding of the process.

 

[yungman]

OK,

1) I just took a big folder called Boot1 from the USB drive (that is like 2.7G) and put it on the desk top.

2) Then I put the Boot1 again from USB drive into each of the sub-folder inside the Boot1 folder on the desk top( So it's Boot1 into each of the sub folder inside the Boot1. )

3) I just keep doing that until I got a warning the disk is full. Then I choose the option of cleaning disk and let it free up more space. Then load in more from the USB drive.

4) I then go to my computer, I notice the Windows7_OS(C) drive is getting full with 0B left, all the 96.1GB are filled.

5) The Lenovo_Recovery (Q) drive is still have room. So I copy Boot1 into the Q drive. Then did the same thing copying Boot1 into the Boot1 inside the Q drive until it gave me a full warning.

6) Then I went through the disk cleaning, and fill more. Now it shows only 100KB free space.Question, You think I wiped the old files yet?

Thanks

 

[yungman]

If I manage to erase all the old files, all I have to do is delete the Boot1 on the desktop ( it's like over 46GB in size) and delete Boot1 in Q drive. I should be done and free back up all the space.

You think this will do it?

 

[jedishrfu]

No! You doing this will only give you a false sense of security.

What don't you understand here?

You ask a question, we give you an answer that you don't like so then you pose other methods that we know are plain wrong for numerous reasons otherwise we would have mentioned these techniques.

There's nothing more to say here either you use a tool that is designed for deleting data on your disk thru multiple write passes of random data or you don't that is your option.

Physically as data is written to a disk the head wobbles in the track meaning your data may be still present on the track edges that's why the multiple writes and that's why it must be different random data each time.

Your method of using simple data copies to fill the disk, deleting them and filling it again won't overwrite tracks marked as bad or won't overwrite directories and file meta info and other stuff that may be hidden for variuos reasons. You need a tool that works at the track level.

However, you could remove the drive, physically destroy it and replace it with another.

 

[phinds]

No! You doing this will only give you a false sense of security.

There's nothing more to say here either you use a tool that is designed for deleting data on your disk thru multiple write passes of random data or you don't that is your option.

 

[yungman]

No! You doing this will only give you a false sense of security.

What don't you understand here?

You ask a question, we give you an answer that you don't like so then you pose other methods that we know are plain wrong for numerous reasons otherwise we would have mentioned these techniques.

There's nothing more to say here either you use a tool that is designed for deleting data on your disk thru multiple write passes of random data or you don't that is your option.

Physically as data is written to a disk the head wobbles in the track meaning your data may be still present on the track edges that's why the multiple writes and that's why it must be different random data each time.

Your method of using simple data copies to fill the disk, deleting them and filling it again won't overwrite tracks marked as bad or won't overwrite directories and file meta info and other stuff that may be hidden for variuos reasons. You need a tool that works at the track level.

However, you could remove the drive, physically destroy it and replace it with another.

The one you suggested with wipe the disk to the default condition like a new computer. I have programs that i don't want to do over. I just want to permanently delete some files.

Any program that can delete files without erasing the existing programs loaded?

 

[phinds]

I don't understand if I fill up all the space, why can't I erase all the old files? Can you explain?

He already HAS explained. Read what he said.

 

[yungman]

How about this one, I read the description, sounds like it will permanently delete files but leave the programs and others alone.

https://www.easeus.com/partition-ma...ete-files-from-computer-without-recovery.html

 

[yungman]

He already HAS explained. Read what he said.

Yes, I read it, I read the first version without explanation when I respond. Now is just how to delete files without erasing the installed programs.

 

[sysprog]

If I manage to erase all the old files, all I have to do is delete the Boot1 on the desktop ( it's like over 46GB in size) and delete Boot1 in Q drive. I should be done and free back up all the space.

You think this will do it?

The Data Shredder 1.0 program (on the Hirens utility USB that you used for your Windows password concern) can erase disks and files, and can also wipe free space.

 

[sysprog]

How about this one, I read the description, sounds like it will permanently delete files but leave the programs and others alone.

https://www.easeus.com/partition-ma...ete-files-from-computer-without-recovery.html

Yes.

 

[sysprog]

If I manage to erase all the old files, all I have to do is delete the Boot1 on the desktop ( it's like over 46GB in size) and delete Boot1 in Q drive. I should be done and free back up all the space.

You think this will do it?

In this post you don't adequately distinguish between erasing and deleting:

The term 'erasing', or 'wiping' usually refers to systematically overwriting the data (typically at least 3 times including with all 0s and with all 1s) in the defined object, so as to make the information previously there no longer appreciably there, and consequently not retrievable therefrom.

The term 'deleting' usually refers to simply marking the areas occupied by the object as available for re-use, without overwriting it, which leaves it potentially recoverable.

 

[yungman]

In this post you don't adequately distinguish between erasing and deleting:

The term 'erasing', or 'wiping' usually refers to systematically overwriting the data (typically at least 3 times including with all 0s and with all 1s) in the defined object, so as to make the information previously there no longer appreciably there, and consequently not retrievable therefrom.

The term 'deleting' usually refers to simply marking the areas occupied by the object as available for re-use, without overwriting it, which leaves it potentially recoverable.

Yes, I want to erase so nobody can retrieve the files.

I have a question. I know it's not as good, but if I fill all the free space with some big files, then delete them all, and then refill all the space again. If I do it like 3 times, doesn't that pretty much erase all the old files?

My computer has a SS drive, it's only like 128G, the free space is only 48G on the C drive and like 7 or 8G on the recovery Q drive. I can do this fill and delete in one hour. If I do this 3 times, will that pretty much erase the old files?

I understand there are tracks and all, but if I do it 3 times, that should destroy whatever originally in it.

 

[MikeeMiracle]

Download a program called "sdelete" its free from Microsoft. You can use it to overwrite the free space on your hard drive so you don't lose anything that is not already deleted. It's a command line tool so you will have to lookup the syntax to run it. I would recommend overwriting the free space 7 times to be safe. That will make your data safe from everyone bar intelligence agency's ability to recover it.

The only true way to get rid of everything even past an intelligence agency's ability too recover it is to shred the storage media into tiny pieces.

 

[sysprog]

Yes, I want to erase so nobody can retrieve the files.

I have a question. I know it's not as good, but if I fill all the free space with some big files, then delete them all, and then refill all the space again. If I do it like 3 times, doesn't that pretty much erase all the old files?

My computer has a SS drive, it's only like 128G, the free space is only 48G on the C drive and like 7 or 8G on the recovery Q drive. I can do this fill and delete in one hour. If I do this 3 times, will that pretty much erase the old files?

I understand there are tracks and all, but if I do it 3 times, that should destroy whatever originally in it.

I was trying to say essentially the same thing that @jedishrfu said and that @phinds re-iterated.

If by "fill all the (48 GB free) space with some big files" you mean write files that contain data, e.g. if you put 48GB of zip files there, and then delete the files using a normal delete command, on HD devices, the zip file data would still be there, but whatever data was previously there would have been overwritten with the zip file data.

On SS devices, the situation is rather different, in that every block is erased before it is rewritten, and the OS by default does the erasure whenever a file is deleted. Even so, SSD buffering and 'wear leveling' can cause data to be present on the device in a state that isn't normally reported to the OS.

What you propose is not a good way to implement the purpose that you originally stated was what you wanted to accomplish.

If you would like some assistance with using appropriate software tools to obliterate the data in the free space, while leaving your system and program environment undisturbed, please post again.

 

[MikeeMiracle]

Ahh, you have bigger issues with an SSD. With magnetic media the data stays where it has been written to. SSD's actively move data around at a low level to prevent over usage of certain flash chips, the OS is not aware of this process.

Without understanding exactly how data is written at a very low level, I would suggest you take our advice about wiping data with dedicated programs designed for the task.

The sdelete program I mentioned was sufficient for wiping government level data below secret level and it's your simplest solution.

 

[pbuk]

I don't want to remove the disk as it has a lot of programs useful installed already, just want to erase the data files.

Then there is no point worrying about securely erasing just the files you know about because the installed software will have left your confidential information all over the disk, particularly in the Windows Registry.

You have to do a clean install of Windows, this should not be a big deal.

 

[jedishrfu]

We like to think of hard drives as blackboards where data is written in some gridded area on the board and then erased where each blackboard grid represents a track sector on a hard disk.

Sadly or happily this is not how it works. When a file is deleted the area is marked as available, the system does not overwrite the data, it simply returns the track sector to the system to be used once again. In the blackboard analogy, the area is marked with a strikethrough line but the data is still visible. (The happily part is for when you accidentally delete a file there is a good chance you can recover it if you don't wait too long).

As you make new files, the system will allocate track sectors from unused space, it won't go back as reuse the free tracks until all unused space is used up. This is done to prevent the overuse of one area of the disk. In the blackboard analogy, it means the data is written to blank grids on the board until there are no more available and then the strikethrough grids are used.

Because of these write strategies to limit overuse, your file data will be scattered all over the disk. If you recall from time to time, you had to defrag your disks to improve disk performance. Defrag would move track sectors around to make them more contiguous so as to minimize disk head track seek movement. In our blackboard analogy, it would mean reorganizing the blackboard grids so that all strikethrough grids are squeezed out, and only saved data is in each grid square followed by all the free/empty grid squares.

 

[sysprog]

Here's a paper showing some of the issues involved in erasing data from SSDs:

https://www.usenix.org/legacy/events/fast11/tech/full_papers/Wei.pdf

Reliably Erasing Data From Flash-Based Solid State Drives

Michael Wei∗ , Laura M. Grupp∗ , Frederick E. Spada† , Steven Swanson∗

∗Department of Computer Science and Engineering, University of California, San Diego
†Center for Magnetic Recording and Research, University of California, San Diego ​

 

[yungman]

Good late morning.

I read through the replies again. This is more for my curiosity to understand better, here are my questions:

1) For mechanical HD, when writing, the head wobbles, so when writing, the tracks are not perfectly straight. So when overwriting, the head won't wobble exactly like the last tracks, so the edge of the tracks of the old data are NOT being erased. So reading the edge might be able to read back the old data even though it's supposed to be erased. Is this correct?

2) If 1) is correct, this does NOT apply to SS drive as SS drive is just flash memory, there is no head to wobble, no edge to read. They are memory cells, there is not edge to retain data. So if you erase, you really erase. Is this correct?

3) When I said I fill the free space of the C and Q drive with big files, That will leave gaps. But if I fill with a big folder with many many small files, I should not have problem. Then when the drives gets full, I fill with even small files, that should fill in a lot of small gaps. Correct?

4) When the drives are getting very full, if I go in and do disk clean up to free up space, that should rewrite a lot of the files to free up the small gaps, that is like writing over the data again and again to erase the old data in the gaps.

I don't mean to be stubborn and not listen. First I want to understand the reasons. Secondly, if I can do it myself, I don't have to rely on outside programs. I am paranoid after hearing about Tik Tok and other programs that actually save inform and transmit back to spy on people. If I can do it the dumb way, it's not exactly crazy.

I am pretty sure I have the SS drive instead of mechanical HD, it's only 128GB, also, I can fill 40GB in like 10 minutes. I don't think mechanical HD can do that. Like I said, my so called "BIG" files is really like a big folder contains numerous small files, like data sheets, schematic pdf etc. when it's geting full, I fill with small folders, then with individual pdf files. Then I do disk clean, then repeat the process until it shows 0Bytes available.

It only took like 1 hour to do this. AND I already did this 3 times already. That should do it. Correct?

thanks for your patience.

Alan

 

[sysprog]

Good late morning.

I read through the replies again. This is more for my curiosity to understand better, here are my questions:

Belaying for now indulging of your curiosity $-$ in order to accomplish your stated purpose, please read and understand the following procedure, and if you are satisfied, carry it out:

​

CAUTION: This procedure includes completely wiping/erasing your SSD. Be sure that you have a good backup before you wipe your SSD. Follow the entire procedure EXACTLY, and if you are unsure about the backup, or about any part of the procedure, before running of the SSD erase utility, abort the procedure.​

​

0: If you already have a full-physical-disk backup/restore procedure that can omit 'unused' sectors, you can substitute it for DriveImage XML in steps 1, 2, and 7.​

​

1: Download the free version of DriveImage XML from http://www.runtime.org/driveimage-xml.htm. Install it onto a bootable USB device. You can instead run DriveImage XML from the Hirens USB device that you made for solving your password problem.​

​

2: Connect an external drive, and make a backup of your SSD drive onto the external drive. Read and follow the instructions for making the backup. Your C: and Q: drives are logical drives that are really separate partitions on the same SSD. Use physical backup of the SSD rather than logical backup of the 2 logical drives, so that you don't have to reconstruct the partition table when you're ready to restore. Do not use 'Raw Mode', because that will back up 'unused' sectors that you don't want, thereby defeating the primary purpose of the procedure. If you don't have a large enough external drive, with enough free space to accommodate the backup, you can use DVDs, but at 4.6 GB each, it will take most of a 25-pack, and it'll be a lot slower than writing to a HDD.​

​

3: Verify that the backup ran correctly.​

​

4: Shut down your HP 400 Series machine (I'm assuming that this is the same machine that you had password problems with).​

​

5: Reboot the machine, and hit F10 repeatedly during the splash screen to go into the BIOS Setup.​

​

6: Select Security. Then Select Hard Drive Utilities or Hard Drive Tools. Then select Disk Sanitizer or Secure Erase. (The utility is also available for download from HP: sp40109.exe) The manufacturer-provided SSD erase utility spares 'wear' on your SSD compared to overwriting methods, because it doesn't 'write' anything $-$ instead, it sends a voltage spike to the SSD, causing a 'flush of all stored electrons', effectively producing a 'reset' to an 'erased' state.​

​

7: After you confirm the erase, reboot from USB, and run the DriveImage XML restore.​

At that point your SSD will contain all and only what you didn't delete. Insert an administrator ID for your granddaughter. Breathe.

 

[DaveC426913]

It seems to me that there's a penny-wise pound-foolish thing happening here. Master-level data wiping requirements but no consideration for other locations of user-specific content.

The OP wants to keep the software app, while only erasing data. The line between software and data is more and more blurry these days.

If the OP wants a level of wiping that is essentially pro-quality, he is not going to get that by leaving software on the computer - even if he wipes data.

Examples:

1. It can be a simple matter of the intended recipient opening up, say, Word, and looking in the Recent Files list and inadvertently seeing 'Twilight Slashfic-fap.doc' as the last doc accessed (despite that file having been erased).
2. Some programs store data with software. An HTML page can embed an image in CSS as a string. Simply opening that HTML page would reveal the image. No data wiper will find that if it's not in a well-managed location.

Sure, setting up a new user and deleting the old one ought to clear your personal settings, but really there's no way to be sure. Some programs don't abide by the Windows standards, and don't store all user data in the user folders. Some store their data in their own application folders. You won't be able to clear those easily while still keeping the software intact.

The level of expertise required to literally recover wiped data is much higher than the level of expertise to find remnants of previous use, as suggested above.

I don't think there's any way to guarantee what the user wants. Either wipe the drive completely and start fresh, or reconcile your expectations with a small but non-zero chance of getting busted.

 

[yungman]

Hi Guys, Thanks for all the suggestions. I am giving the computer to my granddaughter only, there's nothing illegal, secret or high value information. My wife used the computer before, there are bank account info, tax information etc.

I learn a lot on this, I understand what I did is not good enough, it's just where to draw the line. I fill 3 times with big files, but after I read the information here, I learn using big files is NOT a good idea as it leaves gaps in between. So the 4th time, I just put a lot...I mean a lot of small pdf files into a folder to make up 1.2G size. Then I copy that folder over and over until the warning message. I did disk clean up to free space, then fill more.

When it get to very full, I started copy small files a few at a time, clean disk until there's no room to even put a 20KB file. Yes, it is much harder to get full, but I think I write over a lot more complete this time.

I am not trying to be stubborn, like I said before, after I read news like Tik Tok and other software can spy on people, I just rather do a lesser way than to try to run external eraser if I can help it.

So I erase and filled 4 times already. I hope it does count for something. I was hoping I can get instruction within Windows to erase, but I guess not.

Thanks

 

[Vanadium 50]

A lot of ideas are getting twisted together here.

First, there are levels of security:

• Keeping your little sister out
• Keeping a determined criminal out
• Keeping a major world government out

In the middle tier, a drive can be recovered for around $1000.

The idea of residual magnetization goes like this. Data is digital, but the read/write mechanism is fundamentally analog. Suppose what's recorded is 10101010... Then it's erased to 00000... but what might actually still be on the drive is 0.1-0-0.1-0-0.1 etc. Now let's write 110110110. What might actually be on the drive is 1.1 - 1.0 - 0.1 - 1.0 - 1.1 - etc. In principle one can recover the original 10101 pattern. In practice, this is more complicated, and it's not clear it can be done by anything less than a major world government.

Disk erase software writes random patterns multiple times. It's unclear how many passes it takes to keep major world governments out: DOD used to say three. Well, if the same software protects you from likely threats with one pass and unlikely ones with three, why not use three when you can?

Things are somewhat different with SSDs, but that's not the subject at hand.

Now, if you don't reinstall Windows, Windows may well keep its own copies of various pieces of data. It won't even keep your little sister out. So your answer is simple - use a utility to overwrite the disk, ideally three times, and then reinstall Windows.

 

[rbelli1]

So I erase and filled 4 times already. I hope it does count for something. I was hoping I can get instruction within Windows to erase, but I guess not.

A double NSA KGB super duper wipe of the free space does nothing for the file slack. Or anything you missed deleting. Or backups or temporary files made by Windows or your other software. Or leftovers in hibernation and swap files. Or any of the spare sectors on the SSD. Or something else I or the other posters here forgot.

Your sort of almost free space wipe is even less effective.

Nuke it from orbit and reinstall like Vanadium 50 and others have suggested.

BoB

 

[sysprog]

A double NSA KGB super duper wipe of the free space does nothing for the file slack. Or anything you missed deleting. Or backups or temporary files made by Windows or your other software. Or leftovers in hibernation and swap files. Or any of the spare sectors on the SSD. Or something else I or the other posters here forgot.

Your sort of almost free space wipe is even less effective.

Nuke it from orbit and reinstall like Vanadium 50 and others have suggested.

BoB

The DBAN product page to which you linked says "It cannot detect or erase SSDs"; however, it has a link for a trial for a drive eraser product that it says works on SSDs $-$ I think that @yungman would do better to use the manufacturer's (HP's) readily available method.