Q I wish to dispose of an old computer and I understand that the best way of protecting the personal information on the hard disk (my bank details and so on) is to remove the hard disk and break it up with a hammer, and then the other computer parts can be used by a third party. Can you advise how to go about this process?
Neil Crombie

A The rather odd advice to smash your hard disk if you’re getting rid of a computer was recently propagated by a national magazine (not one related to Computeractive, we hasten to add).

While it’s certainly one way of making sure the data on your disk can’t be accessed, it’s not the most practical. For one thing, it’s dangerous – there’s a risk of being hit in the eye by a small part flying off the disk’s casing – and second it is considerably more trouble than it’s worth.

Let’s go back to basics: the reason you need to make data unrecoverable is that, because of the way hard disks work, deleting something doesn’t really mean it’s gone. When you delete a file in Windows it remains on the disk but the computer ‘forgets’ about it. It’s still easily recoverable. Even formatting the hard disk, which wipes it clean, leaves traces of your old data which, again, is still recoverable with dedicated software.

There is software available, though, that will not only wipe your hard disk clean but will overwrite it with random patterns of data so that the old data (your confidential files) is truly hard to recover.

There’s some argument over how thorough the software needs to be, but one of the most popular free tools, Eraser, allows you to set a number of ‘passes’ – that is, the number of times it overwri tes all the data on the disk.

How many you use is up to you, but obviously the more passes, the longer it will take. One or two is probably enough for most people, since criminals are more likely to move onto an easier target than waste time recovering masked data.

Either way, using Eraser or other software (most all-in-one utility programs, disk tools software, system tweaking or tune-up software and some security programs will offer the same features) is certainly easier than taking a hammer to your disk.