Whoever is planning to sell or scrap their old computer, used mobile phone or storage media, should make sure that all files are really deleted.

Improvements in capacities and better performance of computers, mobile phones, PDAs, or storage media leads to a faster exchange of equipment and many companies and individuals are selling, giving away, or scrapping their still often functioning devices. Be cautious, as the buyer can get hold of confidential information, even if the previous owner believes that they deleted all documents properly.

In general it is not enough to just empty the trash as it does not remove files from the hard drive, just the references to them. Furthermore, please remember that application programs, such as Microsoft Office, automatically generate backup copies of edited documents, which usually do not appear as a file whose data is yet available. Most users, therefore, are not aware that even deleted documents on the hard disk are easily recoverable. It is recommended to securely delete all personal information and data sources stored on old equipment when sorting them out.

Here are the most basic rules:

  • Override hard disks and floppy disks repeatedly: The Linux and Mac OS X operating systems have serial-production special programs; for Windows there is suitable software from Acronis, Steganos or Ashampoo, which can make targeted individual folders and files unreadable.
  • Destroy CD-ROMs and DVDs: An inexpensive solution is a small office document shredder with an additional CD disk shredder.
  • Override memory cards and USB sticks: The contents are no longer legible after a single complete overwrite.
  • Put mobile phones back into their original position: Delete the phone memory which contains telephone book entries and SMSs and set the mobile back (reset) to the factory settings, and don’t forget to remove the SIM card!

By Daniela La Marca