according to
The Wonders of the File System Object
http://www.15seconds.com/issue/000816.htm
"............
The FSO does have some weaknesses - for instance, it stumbles on binary files. This includes MS Word documents, many image formats, and, unfortunately, a lot of other files. You can still, however otherwise manipulate these files - move them, delete them, etc. What you can't do is open, read, or write to them. Given some ingenuity, a method could be devised to use the FSO to play with binary files, but many will find it easier to simply use the old Open method (check out MSDN for an example).
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