Or you can type 'autonuke' to securely erase all drives.
When you boot your computer with DBAN, you can choose various levels of secure erasing and select which drives you want to erase, if the computer has more than one. You can securely erase a Mac or PC by making a free bootable DBAN CD or flash drive. After that, some of your data may still be retrievable, but it would take a significant amount of time and expertise to do so. Unless you're worried about corporate espionage or government intervention, three passes is generally sufficient. To make sure your personal data isn't recoverable by reasonable means, do a secure wipe: This not only deletes your data but also overwrites the data a certain number of times, which makes the data much more difficult to retrieve. But if screwdrivers intimidate you or you want the computer to remain functional so someone else can use it, you’ll have to invest a lot more time. You can then install the old drive in your new computer, or put it in a USB hard drive enclosure and use it for backup or portable storage.
When you're recycling your old laptop or desktop, the simplest and most secure solution is to physically remove the hard drive.
