I'm trying to format my external hard drive so I can get all the junk off to use for Time Machine. In Disk Utility when I try to format it, it gives me an error: I can eject it from Finder. I've tried restarting, unplugging and plugging it back in but I keep getting this error. Any ideas? I'm using an enclosure w/ USB 2.0. I'm using the original hard drive that came with my Macbook (Seagate 80GB drive) for the external.