WipeDisk

If you have sensitive information that you wish to remove permanently, so not even the best data recovery software can get a single bit of it back, then try this application. WipeDisk is a small yet powerful application that properly erases physical and logical disks. This application can wipe both complete hard disks or just a single partition, safe and fast. For example, if you are replacing the hard drive of a server with a new one, don't just throw away the old hard disk, first make sure that the information it used to store is unrecoverable.

WipeDisk works by overwriting all the sector of the hard disk or the partition that you want to clean up, ensuring a forensically correct erasure of data. The application supports 12 different algorithms or methods to delete your data, a lot of them are standards of many security and government agencies, like the US Navy, US Force, or the US Department of Defense. Each defines a different way in which the data will be overwritten and how often; normally the last pass will be done with only 0 (zeros). If anybody wants to use the drive again, they will have to format it anew.