i have just bought a 2TB seagate expansion external drive, i want to use it for putting movies, photos, music, and backup of rmy Mac OS X 10.7.4. Now my friend tells me that i need to format it first...well i have no idea how to to do that, and the hard drive did not come with any directions. I would also like to take it with me when i go to visit my daughter, so i can copy all the pics of my Grandchildren from her Windows 7 PC....help to do this will be very much appreciated as i have no idea what so ever.