"Cannot access file" in win7 32bit

I tried to do a folder backup from my pc to a network drive using “sync copy” way.

It ended up almost all files cannot be accessed and only a few files were copied.

In the log:
Processing new file: “\STUDIO-NAS\Public\wai\projects_full_files\projects.…upgrade.php”.
Processing item \?\C:\projects.…upgrade.php using raw read…
Cannot access file \?\C:\projects.…upgrade.php

tried to run as administrator, “raw read”, “volume shadow copy”, still the same.
Can any one help?


Were the files in use at the time? Where was the sync copy destination?

Thank you.