Windows Backup Error (0x80070002) When Adding Custom Libraries

I’ve encountered an issue with Windows Backup in Windows 7 that, upon some research, appears to be both a) not uncommon and b) not new; it seems this has been an issue since the new backup tool arrived in Windows Vista. Users have posted in Microsoft’s forums, and Microsoft has responded with workarounds, but no indication that a fix is forthcoming.

For those with this issue (your backup completes successfully but “some files were skipped”, and the log shows something like “Backup encountered a problem while backing up file C:\Windows\System32\config\systemprofile\My Projects Error:(The system cannot find the file specified. (0x80070002))” — the “My Projects” would be the name of a folder you added to a library you created), the fix is relatively simple.
  1. Either click the Change Backup Settings link from the error message, or open Backup and Restore and click Change Settings.
  2. Choose your destination drive.
  3. “Let me choose.”
  4. Uncheck any libraries you’ve created.
  5. At the bottom under Computer, expand you drive and work your way to the folder(s) contained in the libraries you disabled in step 4. Check each one.
  6. Click next, make sure all your files are listed, and click Save & Exit.
  7. Try your backup – it should complete successfully, with no files skipped.