Error in backup 0x807800C5

There are two different things going on here:

For Win 7 and win 8 when u get the error that applies to a specific file or parse point not being backed up it usually means some file is in quarntine by a virus program and therefore can not be read.  There are various possible solutions most center around deleting everything from quarantine.  Before you do the back up.

For Win 8 only: The Win 7 back up program included with win 8 does not support backing up a image file to any kind of NAS device (UNIX, Linux) .  Internally the program gives an error that the NAS device has an incompatible sector mapping type.  You can backup to a hard drive that is attached to a different windows machine and then back up that file to your NAS.  Convoluted, but it works.  Should MS fix this?  Probably yes but their current philosophy seems to be that people should be using  win 8 backup (Files within Libraries only)  I hate the whole concept of Libraries, (and Play Lists)  They make no G D sense to me. But that's just me.

Ich kann auch auf Deutsch eklären.  Aber ich glaube es ist bei dir nicht nötig.  Dies hat mir auch Länge frustriert.

I completely agree.  Libraries cause too much confusion to end users IMO.  I've never used them, nor do I know anyone who has used them, that has liked using them.  The QNAP I'm using has iSCSI support - so I mapped a LUN and do my backups to that disk for now.  I hate eating up a large chunk of space for backups which doesn't fill the whole LUN... but for now, that's my temp solution.  I really hope MS fixes this - or that QNAP comes up with a different resolution.  I got confirmation from their support team that they know about the issue and hopefully will have a new firmware by the end of Dec that could fix it.  *fingers crossed*

 Should MS fix this?  Probably yes but their current philosophy seems to be that people should be using  win 8 backup (Files within Libraries only)  I hate the whole concept of Libraries, (and Play Lists)  They make no G D sense to me. But that's just me.

I totally agree with you there. I too never got used to libraries. Also, i don't quite get the concept of Win 8 Backup, since you have to reinstall everything in case of harddrive crash. 

I often use files (e.g. scripts) outside of my users folder (e.g. on drive D:) so they're easier to reach on the command line. I guess they also wouldn't be part of the backup then? For all those reasons, I would really like to go back to using Win 7 Backup.

For now, I'm using Acronis True Image, which is working well so far, but I don't really like the idea of backing up to a proprietary image format.

of Win 8 Backup, since you have to reinstall everything in case of harddrive crash. 

Not only reinstall but perform all updates and redo all of the configurations.  I don't know about you, but redoing preferences for a program that I normally just have running in the background frequently takes 1/2 an hour or more as I research the settings.  Reinstalling all windows updates alone forget Adobe, Java, Sony, Nero etc. can take hours.

It works without including system image...