Thanks for the suggestions Rharv and PapaMikie. I tried it with both USB connectors at the same time and it still didn't show up as being plugged in. The most confusing thing is on my desktop, one of the tries, for a few seconds had the AutoRun box going and then vanished again. MyComputer still doesn't give any indication it is even plugged in to the computer. So it looks like it's not just the data on the hard drive that's missing, it seems that the hard drive is now just a box of metal.