No, In Windows Explorer if I view the file attributes, some files have an
"O" as attribute., justlike "A", "S", "R" and or "H"
This "O" I can not reset.
That is an extented NTFS attribute. It stands for "Offline". You
shouldn't change the attribute, it means the actual or "real" file is
stored remotely.
The original could be on a file server, on the internet somewhere, on
your laptop... I believe Remote Storage is involved in these "O"
attributes and that File Synchronization uses the attribute to know
which files to synchronize (I think). I do believe that (some) backup
software also pays attention to the attribute in order not to backup
these files and thus corrupt the original versions or pay special
attention when backing them up. I'm not sure how to change the
attribute the "Microsoft" way but I know that there are third party
tools or software that can change the attribute. Example: