Hard Disk Disposal

Helps With

Helps With
  • Privacy
  • Protection of personal data
  • understanding the risks when disposing of disks

When you dispose of a hard disk, or any computer containing a hard disk then you should consider what data may be still on the disk, and whether this leaves you vunerable. Your hard disk could contain:

  • all your documents
  • bank records
  • credit card details
  • bank login details cached
  • a history of all the website's you've visited
  • all your personal emails

Destroying a disk

Even if you delete all the data from a hard disk, it is still possible to recover it. The hard disk may even have failed, but a determined person may be able to get at the data using anything from the simplest techniques (putting the disk in a freezer for a few hours) to the most complicated recontruction of the disk electronics,or replacing heads and motors. There are two main ways to destroy the data.

  • Physically destroying the surface of the disk
  • Running data destruction software

Destroying the disk

To do this you have to take the disk out of the machine, unscrew the covers and scratch / bend the disks. Each hard disk can contain several plates, each site of which need to be destroyed.

Disk Destruction Software

When you delete a file, the file is not actually deleted. First of all it is moved into a recycle bin. Even when delete from the recycle bin, all that happens is that the first character of the filename is erased. Disk destruction software will repeatedly write and overwrite the whole disk so that all data is removed.


There is a lot of scaremongering about things like this. The chances are that no-one is that interested in your data, that the probability of finding your credit card details are small enough that it's not worth the cost of recovering the data and the time to find the information. It's up to you to weigh up the risk verses the cost.