I would like to switch from rhino6 to rhino7. So I downloaded rhino7 but when I am asked to enter my license key it is not the right one. Mine starts with 60 and the one I need for rhino7 must start with 70. How do I update my license key?
Buy an upgrade…
I’m already paying for a Rhino6 license. It seems to me that to use Rhino7 I don’t need to pay again. Is not it ?
You do need to buy an upgrade to use Rhino 7. You will however be able to use both Rhino 6 and Rhino 7 on the same machine, even at the same time on that same machine.
Ok i understand ! Thanks a lot for your answers ! 
Service releases within a Rhino version are free. They fix bugs.
Version changes add new features and are not free.
Version Upgrades are generally priced at about 1/2 the price of a new license.