How to erase the contents of a crashed Hard Disk?


Active Member
I have a couple of HD's which have packed up. BIOS no longer detects them and there's no way I can get into the HDs' contents. They are still under manufacturer's warranty, so I'm gonna send them back for replacements. However, there is highly confidential data in them which I don't want the manufacturer to access, in case they try to get the drive working again, recycle parts or refurbish the drive for resale, etc.

How can I erase the entire contents of the HD's, before I return them to the manufacturer? Since I have no way of viewing the contents, I have to be confident the method erases the HD's efficiently.



If the bios no longer detects them then they should be well screwed. A manu won't be interested in your data - imagine the law suits - merely hardware recovery if possible but it's more likely they'll ditch the disk/s at the least or the entire thing anyway if it's that bad.
However, if you can at least get the bios to see them you could use disk killer from these guys http://www.killdisk.com/ to do a low level wipe. There's a free downloadable floppy exe. disk.


It cost a lot of money to recover data for a screwed up HD I do not think the makes will go to the trouble just to glean what most probably be useless info to them.


Well-known Member
You have to fully write over a disk about 7 times to make to unrecoverable.


Well-known Member
Depends what you mean by "Highly Confidential".

For hard disks that have contained "Restricted" or lower material, then, as Jeff says, you can overwrite them a number of times (I forget exactly how many is recommended - 7 sounds right) and be confident that noone is going to go to the bother and expense of recovering it.

For anything of a higher security rating, then you are looking at either sending it off to a specialist firm, or taking a hammer to it...

I'm guessing that encaser & Jeff's suggestions will be fine for you.



The program I suggested is rated by US DoD bodies as rendering material unreadable, so I doubt the manu's of your HDD will bother trying to piece anything together - that is unless you have the formula of oil from water:)


Novice Member
Originally posted by Dr.Rock
How can I erase the entire contents of the HD's, before I return them to the manufacturer? Since I have no way of viewing the contents, I have to be confident the method erases the HD's efficiently.
Simple answer is you can't.

If the BIOS can't see them then there's no way you can do anything with them in a domestic environment .. no programs mentioned above are at all useful because the drives just aren't there as far as DOS etc. is concerned. Even if a program were available that bypasses the BIOS, the fact is if the BIOS can't see them I consider it implausible something else could .. again, ignoring the sophisticated devices and methods data-recovery specialists have.

There are many possible types of disk failure, but they all basically come down to these:

1) IDE interface failure, ie. electronic
2) Motor or accuator failure, ie. mechanical/electro-magnetic
3) Head crash, ie. physical damage to the disk platters

You could be able to do something with (1) if you have the knowledge and wherewithall to swap IDE cards, anything else pretty much out of the question. In failures 1 and 2 the media is probably in tact, failure 3 of course will damage some but probably only a small amount of data.

You'd be right to expect that much data is probably recoverable. If you're really concerned about that data falling into the 'wrong' hands and you absolutely can't get the BIOS to see them, IMO you've no option other than to physically destroy them.


Novice Member
You could try this. Bring them to a TV repair shop and ask them to run a degaussing coil over them. This creates a very strong random magnetic field which would probably erase everything. A degaussing coil is used to demagnetise the shadow mask in a colour display tube. The problem is you would have no way of verifying. Don't try to verify this procedure with a good drive as it would erase soft sector marks etc and even a low level format might not recover it.



KraGorn, I said above that if the bios can't see the drives the HDD are screwed and offered the program in case Dr Rock sorts the bios.
As per Muf's suggestion, I wouldn't do that as you may well blow the warranty.


Novice Member
If it's really that important, the data thats on there, then just destroy the disks and buy more.

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