If you’ve lost your key, check your receipt from an authorized retailer (like simMarket, Carenado’s own store, or other flight sim shops), or contact their support with proof of purchase. If you haven’t bought it, you can purchase a legitimate copy from official flight sim add-on stores.
Activation is straightforward:
: Approximately 915MB of available hard disk space for the base aircraft. Core Features & Included Documentation -FSX- Carenado Citation II S550 SP2 License Key