the point is that you neither can NOR need to chmod files on win32 , unless a file is set as 'read-only' then its fair game to anyone with access to that folder.
if you want to keep your script x-platform you can still use chmod()& chown() commands in your scripts windows will just ignore them.
i.e
<?chmod('file.file',0755);?>
will be ignored on win32 and work as expected on *NIX
but you can still write your file