So long as you have a license key (for 15) the demo version will run in full professional mode.
If not you might get a 30 day trial (can't remember) and then it will only run in Demo mode.
If you don't have a license you will have to contact your local Archicad retailer which you can track down through the Graphisoft website.
Barry.
One of the forum moderators.
Versions 6.5 to 27
i7-10700 @ 2.9Ghz, 32GB ram, GeForce RTX 2060 (6GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11