Windows Backup did not complete successfully

This took me ages to discover (and hat-tip to Sarah Bourne for the answer) so I’m posting it as it might help someone else.

If you suddenly start getting this error when doing backups on Windows 7, run a full security scan and kill any quarantined viruse. (I use the free-to-download Microsoft Security Essentials.)

Why the error message is so stupidly unhelpful, and why Windows back-up doesn’t simply carry on in the legitimate assumption that you’d rather not backup quarantined viruses, are just two of the many mysteries of the universe.

2 Responses to “ Windows Backup did not complete successfully ”

Comment by Pat LaFollette

Interesting idea – I had a quarantined virus – deleted it and … Backup failed again. “One of your backup files could not be crated. Details: The request could not be completed because of an I/O device error.” Backup location: My Book (G:) [3TB USB 3.0]; Error code: 0x8078002A.

I am using a brand new Dell Inspiron Windows 7 laptop, trying to up everything on C: (except recycle) and external drives E: & F: (1 TB each) connected via a “plugable” USB 3.0 4 port hub. Over 5 tries, backup has copied 1.56 TB (about right) to the G: drive. But backup has never completed successfully. I noticed that both “data/pat” and all of C: were selected for backup, which seemed redundant. Unselected “data/pat” but made no difference. Backup still failed with same device error. Any suggestions?

Comment by Mike S.

Pat,
Same error code for me when doing the first backup of my home PC to a 3TB My Book. Have you figured it out? I ran virus detect. Will run again based on your virus note.
Mike