The heads in a conventional hard drive float above the platter(s) on a very, Very thin cushion of air. There's a Very tiny amount of side to side play. **If** a head wrote data while all the way over to the right, then overwrote that data while all the way to the left, in theory you might be able to read that original data. One reason for multiple passes is that the law of averages suggests that, using this example, at least one of the overwriting passes would be all the way to the right as well. I think obviously this was more a concern with early hard drives with data not nearly as concentrated as on something current, since tolerances would not have had to have been as tight.

@John Almost the most unlikely story in computing i've every heard. You fill up the hole through the (bend) platters with what?

@ Very unlikely

Unfortunately it is truth.
Files on a broken CD were recovered; parts of it.
It will cost a lot of time to recover.

Maybe the best way to be safe is to throw the HD or whatever in a pot of liquid steel like:
http://www.refdag.nl/polopoly_fs/het_afgieten_van_de_slak_drijvend_op_32_ton_vloeibaar_staal_1_21167!image/499840613.jpg
or in a volcano

Actually this sounds quite plausible. Sure there will be a .45 caliber hole in each of the platters. But what if the data in question is somewhere else on the platters? I suspect there are machines out there specially made to reassemble platter pieces into readable platters.

If I really wanted to destroy the data on a drive:

1) Take off drive covers, etc. until bare platters are exposed.
2) Take 10-15 minutes turning platters cherry red with a propane torch (stay upwind, outdoors).
3) Cool and disassemble the drive on a flat hard surface (asphalt playground comes to mind).
4) Take another 10-15 minutes with a hand sledge hammer turning the drive into dust.
5) Sweep up all remains and dispose of equally in 10 very separate garbage cans.

I believe it would take a time machine to retrieve the data.

"The Mounties went into a house, the owner heard them coming, and put a 45 caliber round through the hard drive. The pieces were recovered, the platters re-assembled – and enough evidence gathered to secure a conviction with a long sentence."

It's not that different in concept that having a vinyl record with a scratch -- every time the needle hits that scratch it might distort the sound or jump etc., but it can often continue playing afterwards. Data is stored on pretty much the entire surface of a hard drive platter -- the only data destroyed would be where the bullet obliterated portions of the platter(s). Now you might not be able to use the original type of read head, but there are ways to read that data. It's not cheap, so it's not done that often, but as you posted, it is possible.

That's why some US government regs [AFAIK depending on dept.] call for completely destroying data storage devices, e.g. incineration.

#7 John, thanks for the interesting tale, but the platters in a hard drive are usually made of glass so a bullet wouldn't just leave a nice round hole the platters would shatter into tiny fragments, recovery would be impossible, maybe your ex-brother in law was in the entertainment corps.

IMHO the absolute safest method would be to save your work on a separate drive/partition, including temp folder storage [for any app used for your project] on that same drive/partition, then wiping that disk/partition when you're done.

Data is stored in small chunks of storage space, so a file will fill up however many, *plus* the last one which is only partially full. Thus if you were to erase the drive/partition free space, I think most wiping apps will leave any old data in those small chunks of space that aren't completely overwritten by a newer file.

There's also the possibility that if previous data is written in a track with a different center line than the overwriting data [AFAIK the reason for multiple passes], that prior data *might* be recoverable. Windows is writing to the hard drive(s) almost constantly, so there's a very good chance that an earlier saved project file might be overwritten *once* as Windows writes or expands a file. That would be the equivilent of a single pass with a file wiping app, with no option for added passes since that would delete the Windows file.

Another option of course would be to use a VM, wiping the VHD file when you're done. Assuming you have a copy of that VHD file saved prior to your project & stored somewhere else, wiping that 2nd copy of the VHD [that you used for your project], doesn't mean you have to start from scratch re-creating the VM when your project's done.

What I will add to Mike's comments above is that if you had information on a drive that you think needs to be shredded rather then use this utility after deleting I would suggest something like ccleaner which has an option in Tools-> Drive wiper-> Free space only-> say Advanced and clear out all out.

If you read the description correctly, it says:
... “Gutman Method”, that probably is one of the best ways to erase data by overwriting it 35 times.

Bubba, are you telling me they've redefined the Gutmann Method as am totally confused by your comment.
If erasing data was a trivial task and failure was of no consequence then using a program I have no confidence in would not be a problem.

I've used DBAN since the beginning of time utilizing all the methods available for that particular software. The reality is that the Gutmann algorithm is overkill for most users. More then enough for the normal user with standard hard drives. The best way to delete data is to use several random-byte passes. 3 passes is plenty. And if you're looking to buy I'd suggest Blancco by the DBAN people. It's probably the best out there.

The best way to delete data is with a hammer and drill.

Not so much overkill as Gutmann states that you cannot be sure how effective it is on a modern drive.
He also states that, "If the encoding is unknown, then writing random patterns is your best strategy."

XP-Man
What are the differences here?
Your statement: ... the Gutmann Method is still the best ... (taken from your statement)
and
... “Gutman Method”, that probably is one of the best ... (taken from the program description)
The difference is; you are saying a definitive statement. ie: 'is the best.'
The program description says; 'probably' and 'one of the best.' They are not claiming it is the best.
Read the program description again and tell me if you are still confused.
I am not here advocating the Gutman Method.
I am not trying to take away from your credibility here, I am simply pointing out an error you made.
To err is human ....
'Nuff said.

Glary DOES integrate into the context menu - I'm looking at it right now, I don't know about the others.

Ccleaner also integrates.

"The file shredder available in Glary Utilities , WinUtilities or Puran Utilities are actually more effective than many specialized File shredding prorgrams."

When the software's job is to overwrite the data [1s & 0s] stored on a conventional HDD, & since methods such as the included Gutman are pretty common, the only difference that I can see between app A & app B are any added features, e.g. File Washer's ability to overwrite using your custom text file.