When wiping hard drives you may see the following screen
If you see this you must unlock the drive before trying to run an Enhanced Secure Erase (or the Purge of the "Purge or Clear" method) ONLY. The unlock button will appear below the start button, and puts the device to sleep for 10 seconds. It should come back up, but not all devices support this function.
If you are not using Enhanced Secure Erase (or the Purge of the "Purge or Clear" method), you can ignore the frozen icon message.
Unlocking the drive do NOT use a credit