To delete data on a hard drive, install and run a utility such as Eraser or DBAN to wipe the drive, notes Mashable.com. Restore factory settings to wipe the entire drive and reinstall the system.Continue Reading
Although sending files to the trash bin on a computer can get them out of sight, it cannot permanently remove data from the hard drive. This can be a problem when sensitive data is part of the equation. To delete data permanently and safely, run through the following steps.
To access the data on other devices and computers, back up the files on an external hard drive if desired.
Overwriting utilities include Eraser, which overwrites individual files; CC Cleaner, which overwrites sections of the hard drive and File Shredder, which overwrites files on Mac OS X devices. Mac OS X also has a built-in overwriting utility called Secure Empty Trash.
Run the utility and select the files or disk sections to overwrite.
When selling or giving away the computer, restore the system to factory settings to wipe the remaining data from the computer if desired. To restore Windows to factory settings, go into the Settings menu and find the Recovery sub-menu. Select the option to delete everything and reinstall Windows. To reset a Mac to factory settings, restart the computer and press the Command and R keys to open Disk Utility. In Disk Utility, select the Erase tab and choose the option to erase Mac OS Extended (Journaled).