I'm really wracking my brain here trying to figure out this issue. A company that do support for recently upgraded both from Windows XP to 8.1 and Office 2000 to 2013 (365) on a new PC.

One of the secretaries had documents in what is now a protected folder in Windows (C:\Program Files\XXXXXX) etc. These files opened fine with Office 2000 (still installed), but when opened in the 2013 iteration, they were missing data going back to a period of time.

The only silly workaround I have been able to discover thus far is to open the file in Office 2000 and then save it to an unprotected folder such as (Mydocuments or Desktop) etc. Opening it in Office 2013 shows the correct data. Even if the file is then copied back to the protected folder and overwrites the original, it then works fine. I can't just copy the files out, they have to be saved individually.

I've even tried modifying the permissions to TakeOwnership of the protected directory structure and the files still open with old data.

Is there anything I seem to be missing here, or is the only solution to save out of directory each of the effected files with Office 2000 first?

EDIT: In case of confusion here it is illustrated with images:

What it looks like when opened from C:\Program Files\xxxxxx in Office 2000



And the same in Office 2013 from C:\Program Files\xxxxxx