I'm afraid I don't know what exactly happens to a perpetual license when a time comes and I need to get rid of an old computer and get a new one?
As far as subscriptions are concerned, there is no problem. What about PL then? Do I actually need to repurchase Terragen for the new machine to have it as a "main" (not "render node")? :-\
Nope, just uninstall Terragen on the old machine, make sure you remove the license key file (you can do "reveal license key" in Terragen *before* uninstalling to find it), and then install on the new machine with the same setup file and license key. Simple as that.
Ahhh, of course... Been some time since I last looked there. Must be the reason why I forgot. :P