Client sent me a Word document. It came in the form of a zip file and I think the cleint may use something like Open Office which does that with files. I happen to have the winzip program on my computer so it insisted on unzipping the zip file and the result was some 20 xml files which were meaningless. I eventually discovered that if I changed the suffix .zip at the end of the zip file to .docx it opened up correctly in Word. Problem solved though it took time. (I did ring the client but they were out and I wanted to make progress).