Our licensing system uses an unique ID based on different elements of the computer, also one of them is the hard disk signature (this particular signature is provided by Windows OS), and each partition would require the license activation (in your case two).
For security reasons, our activation server allows you to activate a license only a certain number of times (5 by default). In case you'll exhaust the maximum number of activations, please send an e-mail to firstname.lastname@example.org and we'll increment the activation counter associated with your license. Just take in mind, it shouldn't be performed many times in a short time period. Thanks for your comprehension.