Ted has an external hard drive that his laptop cannot read, even though the computer can see the drive. Leo says that since the computer can see the drive, the USB connection is working. So it's likely the drive is corrupted. He can crack open the external case, and Leo recommends going to iFixIt.com and input his drive model to find out how to fix it. Then he can connect it directly and run something like SpinRite to see if he can repair it. But it's probably just cheaper to get a new drive. This is why making more than one backup is so important.