What's New in Pinnacle Studio™ 15

In Pinnacle HD Studio 15 for Windows XP, I imported, edited, and made a video movie, but, while the video works, the audio is not working. How do I make the audio work? It is not my PC's fault, as other videos that I have made recently, including just yesterday, after being imported, edited, and played in the same PC, include, along with the working video, a working audio.