Gordon said:
She said "Word Processing" !
Word Processing is NOT Word. We haven't a clue what word processor the
sender used to compose the document that they attached. Couldn't been they
use a PDF "printer" to save their document to a PDF file and the recipient
doesn't have Acrobat [Reader] installed, and nothing that comes included in
Windows will open it.
It is also possible the recipient's host is screwed up in that the .doc
filetype (*if* that is what the sender attached) isn't associated with any
application, even one that is installed that would handle the formatting
within the attached document. So having the same app doesn't mean the
recipient can open it just by double-clicking on the file (which is what the
OP alludes to by the error message) but the recipient should be able to load
the application and then open the saved file.