I just bought a 2TB Seagate Hard Drive to back up my iMac. I connected everything up. Turned on Time Machine (first time I try to use it) and selected the disk I want it to back up to. As soon as the countdown starts to start backing up. A message pops up that reads "The disk was not ejected properly" and the hard drive disappears. I have to unplug it and plug it back in for it to show up again in the finder. When I try to run time machine again, the same thing repeats. I do not know what the problem is.... is it the hard drive (Just bought it brand new) or am I doing something wrong? Please help, I just want to start backing up all my stuff. Thanks