Secure PC disposal

If you're disposing of equipment in your department, please contact your Departmental Computing Officer.

For more information, please see the information at:

Do I need to wipe a PC before I dispose of it?

When disposing of PCs, the question of whether or not to wipe all data on the PC must be considered. Whether this is worth while or not in any particular case is a judgement call for departments to make.

For example, a PC that has only been used by students and has had no data stored on it locally probably doesn't need to be wiped, while a PC that has confidential financial, student or health records on certainly does need to be wiped, and this needs to be considered as part of the total cost of ownership.

How do I wipe the data from my PC?

As for how you do it, most software methods come to down to "boot from a CDROM/floppy and then write lots of data to the disk". Expect this to take several hours to a day for a PC depending on the size of the disk.

While very time consuming, wiping the drive is the only secure way of doing it. Trying to just remove files has several problems:

  • It is very easy to miss things. Either files stored in strange places or temporary files.
  • Files that have been deleted prior to the wipe will still be recoverable.
  • It is usually not possible to pass on a University PC with Windows installed without violating the terms of our Campus Agreement for the use of Windows.
  • For various technical reasons, software to secure delete a file is  less reliable than secure deleting an entire disk

Because of this we do not recommend that you try and just delete specific files.

One suitable (free) program is Darik's Boot and Nuke. This is used by various US Government agencies for secure hard disk wiping. In a University context, unless the machine has had very sensitive data on it, the lower security of the secure delete options are probably a good compromise between time and security.

Physical methods are another possibility for computer disposal but are probably not practical unless you have access to a milling machine/angle grinder or similar to destroy the hard drive when it has been removed from the machine. Removing the hard drive from the PC and hitting it with a large hammer will stop easy access to the data but will not stop a more determined attacker unless you use a very large hammer. The Health and Safety issues of staff using large hammers or power tools on random bits of computer equipment would also need to be considered and a machine without a hard drive has less utility to the eventual recipient.

The final possibility is the give the PC to a company or organisation that will wipe the disk for you and give you a certificate to that effect. There are commercial organisations that will do this. If you're giving a PC to a computer recycling organisation, we suggest wiping the disk first.