Personal financial details are being harvested from old PCs sent to third-world countries and used to commit fraud. Security experts have been quick to point out that you should always clean your personal data from a PC before selling it.

This article appears in the December 07 issue of PC Advisor, available now in all good newsagents.

But just deleting the data isn’t enough, as readily available data-recovery tools can easily restore it. You need to use a secure eraser tool. But as reader Alec Green asked, "Why should I pay for a privacy suite to clean a PC I’m going to give to charity? It’s cheaper to smash the hard drive with a hammer."

Fortunately there’s a free solution to this problem. Darik’s Boot and Nukeis a secure disk eraser that will obliterate your hard drive’s contents. If the PC has a floppy drive, you can download an installation program which will write it direct to floppy disk, then put the disc in the PC to be wiped and start it. If you have only a CD drive, download an ISO image and burn it to CD. You may need to change the Bios settings in the PC you want to wipe so that it will boot from the disc before you can wipe it. Then simply follow the onscreen prompts.

Darik’s Boot and Nuke will completely erase all the hard drives in your PC, including the partition tables. After it has finished, Windows will need to be reinstalled just as if you had changed the hard disk. The only part that is not touched is the host-protected area, which does not contain any personal data.