What I want to do is cleaning hard drive completely and reinstalling Windows 7 (its configurations does not suitable for Windows 10). 'What is the best way to clean the hard drive of my laptop? I'm going to selling it to someone but want to ensure all personal files are securely erased. If you view tech forums or comminutes online, you can see lots of users looking for an easy way to clean storage devices, and here is one of them: Though operating system cannot see deleted or formatted data and the drive looks empty, average users are able to get back lost data easily with the help of hard drive recovery software. Formatting a hard drive does not completely erase data either. Simply deleting files by Shift + Delete or emptying the Recycle Bin does not permanently clear data, as deleted files can easily be recovered by recovery software. However, the fact is that wiping out a hard drive is not as easy as deleting data or formatting hard disk.

You may have already formatted the hard drive or deleted files on it in order to erase sensitive personal data and avoid becoming the victim of identity theft. It's common to most users to sell or give away computer or hard drive when they want to dispose of old device or upgrade to new ones.

Method #3: Clean PC hard drive by physically destroying it.

Case #4: Securely overwrite deleted files only without affecting existing data.

Case #3: Permanently erase certain files or folders on hard drive.

Case #2: Fully wipe a computer internal hard drive that includes OS.

Case #1: Erase an external disk / SD card.

Method #2: Wipe a hard drive using free disk eraser – DiskGenius Free Edition.

Method #1: Completely wipe computer HDD by resetting your PC.

Overview on wiping a hard drive in Windows 10.

How to wipe a computer windows 8.1