Installing br_free.msi - B&R 12 Free

I downloaded a copy of br_free.msi and tried to install it on an XP machine that can't be connected to the Internet. The first dialog box asks for a Product Key and Serial Number and includes a Registration button, which I assume would lead to the required numbers if this machine could connect to a Paragon server.

Is there a way to obtain these numbers using a machine different from the one on which the software is being installed, like registering for a Paragon account? All I could find on the knowledge base about missing serial numbers were answers to posts which assumed that the user had gotten the software on disks.