Authorization of the program allows to avoid appear on the screen the demo message in some missions but does not affect the functionality of the game. To authorize the program you need to get the Serial Number and the Verification Code, which you may find by clicking the button F9 after start the program (but before switching to the pilot mode). Then you need to click the link below, enter these two codes into the corresponding fields and press the button OK. For your convenience these codes are written in the file .../vav02/wrtfiles/sernum.txt in the working folder of the program, so you may simply to copy them from there and to paste into the form.
Currently authorization is free and does not require any payment.
Authorization will last unlimited period of time until you reinstall the operation system within which the program was authorized.