Yikes - I obviously have a learning curve here. I think during the installation process, it suggested that with Option 3 (installing entirely on the computer's internal hard drive), it would take about 100 Gigabytes. However perhaps this was in reference to using the lower quality files. Perhaps I should just stick with the external drive. I just like the idea of being able to use my laptop without the external drive. But I definitely can't provide Band-in-a-Box 1 TB of space on my computer.