You may know that when you delete a file, it doesn't actually get removed from the hard disk. This is because, when an OS, including Windows, attempts to delete a file, it removes the pointer or reference to the file, making it inaccessible to user. However, the low-level data recovery applications can still be used to view and restore deleted data from storage mediums. When file is deleted from the system, OS makes the space, which was previously used by that deleted file, available for new data write operations, and if OS doesn't fill that deleted space, data recovery application doesn't take long to fully restore the data from unfilled tracks. Therefore, it's always advisable to perform a multi-cycle shred operation over entire hard drive to prevent data theft. You could use CCleaner and other data shred/disk wipe applications (
Secure Wipe,
Hardwipe,
HDShredder etc, for instance), to permanently delete the data, but file shredding can't be performed over the partition where Windows is installed. In this post, we will discuss how to fully wipe out entire hard disk, and make the deleted data unrecoverable.