I'm trying to create a system image on an external 500Gb USB HD. I've used the same drive successfully on a Dell XPS12 so I know it works. Unfortunately on the SP2 it starting doing the image, then stops about 2-3 minutes in saying that the disk is inaccessible. I can access the disk and copy files in Explorer with no issues. I've tried formatting the disk but it didn't help. Any ideas?