From Pianoteq faq:
"May I install Pianoteq on more than one computer?
*Yes, you may install it on up to 3 computers of your own. You are not bound to any specific operating system, thus you may install e.g. a Windows version on the first computer, MacOS on the second and Linux on the third.
I bought a new computer. How do I deactivate the licence on the old one?
You can deactivate the old computer in the user area. After logging in, click on the “Manage activations” link. Only deactivate computers you no longer use. Once you deactivate a certain computer, you will no longer be able to activate it again, even if you reformat or change operating system."