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
Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11