So i just bought an iMac, loving it but...i can't seem to save videos or any kind of file for that matter, to my external hd (seagate 320g). i can read files from my hd but thats about, this hd is also being used with a windows ran laptop and would still like to be able to share it between computers, my question is what do i need to be able to a save from mac to hd and still be able to use it with pc?