https://legalshred.com/degaussing-vs-hard-drive-shredding/ The best and most secure method of rendering hard drive information completely unusable is to completely destroy it through hard drive shredding Shredding is a method of physically destroying storage media files by cutting them into small pieces using a machine called a shredder. Shredding can ensure that confidential data from storage media files is sanitized so the drives cannot be reused, as it makes it impossible to recover any data from the shredded pieces.