There are many software utilities that help you to delete data permanently unrecoverable. With Windows 7, you can easily delete all your data safe without having to install any extra tools. To do this, you access the Start menu> Accessories, then right-click Command Prompt and select Run as administrator.

In the command prompt appears enter the following command: cipher / w path and press Enter. In which you replace with the drive letter DriveLetter with FolderName (folder name) on the drive to delete data thoroughly. For example, you execute the command cipher / wd: Private_Data, ie you delete a folder in the drive partition Private_Data D.