I recently bought a GoFlex External Hard drive and I wanted to back up my mac onto it with time machine. I have a couple of questions. First, I have to choose whether i want to us my HDD on a Mac or Mac and Pc. If i choose mac and pc then i wont be able to use time machine. Is there any backup software i can use that will work with NTFS system on Mac (because it formats the drive to NTFS if i want to use it with both mac and windows). Also if i decide to use time machine, will i also be able to use the HDD to drag and drop files (not only for backup) or will it make my whole HDD not usable (except Time Machine)? I also have a question about Time Machine. I have no idea whatsoever how it works and what it does to my HDD. Could someone please explain how it works . Thanks (By the way, every time i use the word "HDD" i mean my external GoFlex Hard Drive).