After the security prompts, you will be asked to restart the computer. During the restart, all hard disk drives connected to the computer will be deleted permanently. The system partition is always left as last - in case you want to cancel the deletion you will still be able to restart the system and continue at a later time. Please bear in mind that a deletion process once started cannot be cancelled.
After completing the deletion, the computer will restart. On the screen you will see an error message informing you that no operating system could be found. You can now install a new operating system or sell it. All data is SafeErased.