All files, settings, applications and the operating system are deleted so that a recovery even with the best file recovery software is impossible. You can delete an entire computer including the system partition without boot media.
[more]If a computer is only used very rarely to create new documents or documents and files are very rarely changed then a monthly backup would probably suffice under these circumstances.
[more]That’s why we developed O&O DiskErase. This makes it possible to safely destroy certain partitions, hard disks or all data on the entire computer at the push of a button.
[more]