The is a unique, 16-digit serial number tied to a physical USB security key (dongle) provided with the DLC series laser controller . Unlike previous versions, EZCAD3 requires both the physical dongle to be plugged in and a one-time software activation using the serial number to function; it will not open in a "demo mode" without these. Key Licensing Facts
The easiest way; just click OK and it verifies via the internet. ezcad3 license key