Think about all the data on your PC; videos of the grandkids playing in a park, photos of your trip to Patagonia (lucky you!), tax records, emails... Now think about whether those files exist anywhere else. If the answer is no, you need to think about backing them up. You could lose data due to viruses, fire, theft, and computer issues.
Chris Taylor, President of the Ottawa PC Users' group will discuss various ways you can ensure your important data survives any catastrophe.