Windows 7: Can't get Windows Backup to work

I have my Win 7 PC set to back up to an external HD and have yet to get a successful backup. The Action Center gives me the message:

Windows Backup failed while trying to read from the shadow copy on one of the volumes being backed up.

When I look in the event viewer, I find the following error:



The backup operation that started at [date] has failed with following error code '2147942405' (General access denied error).

I've searched for that error code but haven't found any useful info. I've confirmed that both the Volume Shadow Copy and SPP Notification services are running. I suspect file permissions may be involved. The files I'm backing up are on both the original C: drive and another internal drive I added. Does anyone have any ideas what the problem might be, or things I should check?

Take a look here:
Error code 0x8100002F and or error code 0x80070002 when you back up files in Windows 7

Windows backup is extremely primitive and touchy, and therefore unreliable.

I'd suggest using "Vice-Versa Pro" or something similar (a backup with shadow copy - "DriveImage XML" is another). VV-pro is great for incremental backups and has an excellent display of the files to be copied.

I agree with flemur: Windows Backup is touchy to a point where I question its use. Who guarantees, that even if the Backup went through without a hitch, that the restore process in times of needs goes through as well.
Because of that uncertainty I don't even bother and use a 3rd party solution which comes highly recommended by many users of this board. just give it a try:

Macrium Reflect FREE Edition - Information and download

-DG

SledgeDG is right, Macrium does have a good reputation from WSF users.

Try this:
Restart the "Block Level Backup Engine Service" service [net stop wbengine &
net start wbengine] make sure this service starts and it is running before
you commence backup