Ok so I have a few questions. I just bought a Western Digital My Passport Essential 500 GB to use with my Airport Extreme router. Questions: 1) My computer says the Passport HDD has 460GB free. Why not 500? There is nothing on it so far? -Answered. Thanks MacDawg. 2) Do I have to use the Disk Utility program to re-format or erase anything to free up more space? If so, how do I do this? The Disk Utility program has so many options and it is sort of overwhelming and confusing. I am a new Mac user and new to this whole "Time Machine" thing..do you guys back it up all the time or just turn Time Machine on once in a while to back up?