I have been trying for weeks now to get Windows 7 to do a simple backup. I have struggled with all sorts of device issues, and since getting those resolved the basic mechanisms of Windows 7 Backup just seem hopelessly incompetent. The latest error message is "The backup storage location is invalid. You cannot use a volume that is included in the backup as a storage location." The message is 100% falsehood. And why does it take 3 days to tell me that after the backup is 50% complete?

What is the target drive for backup?

I can't tell you why, but it is the reason I've used third-party backup and imaging software since Windows NT 3.5. It's well worth the peace of mind and loss of aggravation. Now there are so many free ones, it makes the inclusion of Windows Backup a moot point -- SC Tom

@Milos, I was basically backing up C: to D: I vaguely recall a discussion somewhere that you cannot backup C: to D: because Windows treats C & D as 'special' Using Disk Management, I changed the drive letter from D: to B:, same drive, different letter, and now my backup works. If Windows 7 Backup really does not want you backing up C: to D: then why does it not tell you that at the beginning, instead of failing half-way through after three days of copying data to D:, and emitting a message that makes no sense at all? This failure mode of Windows Backup really belongs on the Wall of Shame. As an aside, Window 8 is totally ludicrous. It is no longer possible from the user interface to comprehend what it is doing and how. So far as I can tell from the Windows 8 Backup UI, it is not possible to save a system image any longer.