Darik's Boot and Nuke (in short DBAN) is a self-contained bootable disk that automatically and completely deletes contents from a hard disk.
It’s most suitable for preventing identity theft. You can use DBAN when you want to sell your old computer or want a fresh installation of OS after a serious virus or spyware attack.
With DBAN, either you’re able to wipe out the whole hard disk contents or can select specific hard drives or partitions for deleting (shredding). To wipe out the whole data type “autonuke” When it loads, or hit Enter key at startup to get option for deleting specific hard drives or partitions.
DBAN might be an appropriate utility for bulk or emergency data destruction. It prevents or thoroughly hinders all known techniques of hard disk forensic analysis.
You can download Darik's Boot and Nuke (DBAN) at source