Hard Drive Destruction- removing all the DATA
Most people assume that if you delete a file from your computer’s memory and then empty the ‘wastebasket’ that is on your desktop (and maybe run a ‘disk clean-up’ for good measure), the file is gone for good.
Not so. In fact, when you ‘delete’ a file from your PC, what you are doing is not erasing the file itself, but simply the reference to it on the hard disk.
The file itself is still there (until it is written over) and can be recovered with the right software. ‘It’s akin to ripping the index out of the front of a book. The actual pages, with all the original information and text are still there,’ .
The ‘deleted’ files can be recovered easily using proprietary file recovery software. Even erasing the whole operating system (eg Windows) still leaves the files intact- and recoverable simply by booting off an install CD.
You can go a step further: delete the files you want to erase, empty the recycle bin, download a huge file which fills the disk and overwrites the space taken up by the old files - and then delete that. But even then, when your old files have been overwritten with new files, ‘ghosts’ of the old data may remain on the hard drive (this in itself is making it a little harder for criminals to recover your data).
Computer disks use a magnetic medium to store information and, like magnetic tape, completely erasing all traces of what was on it is almost impossible.
Military-spec Hard disk Drive destruction machines exist: these overwrite the old files five to eight times (more than 8 wipes is pointless…) in an attempt to obliterate all traces of what was on the disk. But even then there remains the possibility that really determined hackers could gain access to snippets of surviving information.
How can you make sure this does not happen? There are special programs out there which claim to completely destroy files. But if you want to be really sure, you will have to resort to physical brute force and mechanically destroy the drive.
Even this is surprisingly difficult. Hard disks are robust devices, with a chassis made from cast aluminium and stainless steel covers, and though it is easy to destroy the sensitive electronics and the stylus mechanism, the disk itself is quite hard to destroy completely, given that it’s usually made from aluminium alloy or toughened safety glass. The US Pentagon suggests putting the whole thing in a metal-mulcher, which of course we advocate and actively pursue via the use of our 6 tonne hydraulic hard drive shredder.