The attachment control is not a live, writable repository.
To edit an attached document, you must use the "save as" option from the
control menu and save it locally. Then edit and save and then reattach.
If you are just sharing documents it is probably better to have a common
file share or library and just keep the hyperlink to the document in your
form.
Then they access it from a writable location and do not need to update
anything.

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Clay Fox / Microsoft InfoPath MVP
www.InfoPathDev.com / The InfoPath Authority / Downloads, Samples, How-To,
Experts, Forum
> I am working with 2003 InfoPath and need to know if anyone has an answer to
> my question concerning File Attachments. I have placed the control into my
> InfoPath form and it allows me to attach a Word or Excel file with no
> problem. The issue comes up when I try to open the file I attached and make
> changes. It opens as read-only even though the file is not set to ready-only.
> Any help would be very helpful.