Some bundles include a controller and a digital code card. The serial number is on the card, not on the controller itself. Never throw away the card until the software is fully activated.
If you bought a boxed copy of RealFlight 9.5: Realflight 9.5 Serial Number
Do not lose this card. Horizon Hobby does not reprint serial numbers for physical copies without proof of purchase. Some bundles include a controller and a digital code card
If you bought the digital version:
RealFlight 9.5 allows you to install the software on multiple computers, but only one active activation per serial number at a time. To move the license: Do not lose this card
If you forget to deactivate and your old computer is broken or inaccessible, contact Horizon Hobby support. They can manually reset activations twice per year per customer.
Depending on how you purchased the simulator, your serial number will be in one of three places: