In the list that’s shown you’ll be able to select the partitions you want deleted. You can also select the disk itself if you want to delete all partitions along with the non-partitioned sectors. You have the option of either showing or hiding the non-partitioned sectors. When selecting a system drive, a security prompt will appear when you click Continue. If you didn’t select a system drive or have answered the security prompt successfully, clicking Continue will bring you to the selection of a deletion method. If you don’t wish to delete anything, close O&O DiskErase and your selection will be discarded.
To delete the entire computer securely, click Select all (TotalErase).