I got a brand new external hard drive today. After trying to copy my pc's hard drive to the ext. hard drive, it got around 20% complete, successfully copying many files, but then got stuck with an error. Now, whenever I try to copy any files from the pc's hard drive to the ext. hard drive, it always gives this error. Any ideas on how I can fix this? I got 2 other drives a while ago, returned them, and now the exact same thing is happening to this drive.