5.7.4.2.2. Erase the Contents of the Disk Drive
No matter whether the disk drive has valuable data or not, it is a good idea to always erase a disk drive's contents prior to reassigning or relinquishing control of it. While the obvious reason is to make sure that no sensitive information remains on the disk drive, it is also a good time to check the disk drive's health by performing a read-write test for bad blocks over the entire drive.
Important
Many companies (and government agencies) have specific methods of erasing data from disk drives and other data storage media. You should always be sure you understand and abide by these requirements; in many cases there are legal ramifications if you fail to do so. The example above should in no way be considered the ultimate method of wiping a disk drive.
In addition, organizations that work with classified data may find that the final disposition of the disk drive may be subject to certain legally-mandated procedures (such as physical destruction of the drive). In these instances your organization's security department should be able to offer guidance in this matter.