I received this error earlier this week:
-Error EC8F1C50: Cannot create file backup for job: File Backup.
--Error EC8F1F62: Cannot find external device 'Elements'.
From my previous post:
My setup: Windows XP Home Edition (2002) with a Western Digital My Book Essential 2TB Edition External Hard Drive.
We just recently switched out an older external HD for this new Western DIgital 2TB HD. The initial backup on the Western Digital 2TB HD and the error message occured this morning. I have not touched the computer since Friday.
To answer the question you posed to the original poster: the Western Digital 2TB HD is set to backup everything on the C drive.