I have a question about partitioning an external hardrive. what exactly does it do? I have a laptop with windows xp, and a hardrive ,that was required for my course, that is formatted for mac and does not work with windows. I have read that I can partition it to work with both....but all this talk about the size of it confuses me. I want to know what it actually does, and what I can actually do with it. All I want is to be able to edit my videos with the school's macs, put it on the hardrive, come home to my laptop, plug it in and watch or edit further my videos. Can somebody please shed some light on my ignorance. thanks