Unlike some software that uses only a simple text string, Hard Disk Sentinel (HDSentinel) often utilizes a "keyfile" system for advanced activation, especially when an internet connection is unavailable.
: While you usually receive a 15-digit registration code upon purchase, an activated keyfile ( HDSentinel.key ) is the actual file generated during the activation process that resides in the installation folder to verify your license. Hard Disk Sentinel 6-01 Registration Key File