Tell whoever sent it to you to open the document and use Save As to save it
again. At the bottom of the Save As dialog box, in Save As Type, choose Word
97-2003 and then click save. You will be able to open that one.
Word is backwards compatible so if you get a new version of Word you can
open old files. But, someone with an old version of Word cannot open files
created in the new version. Word 2007 uses .docx as the file extension
instead of the previous .doc.
