Project files are used to store all the RAW data you've added (media information, images, effects, tweaks,scripts, actions, etc.).
Luckily, there is a tutorial explained in detail on how to achieve this. Visit the following link to learn about the export procedure to save the contents of the project files into a full high-quality video.
I've watched the video tutorial and although I didn't have any Pinacle experience, I understand exactly how to save it.