It is also possible that the file extension for the file is no longer recognized by the Open With feature of the operating ...

It is also possible that the file extension for the file is no longer recognized by the Open With feature of the operating system. You may need to reset the file name extension association. To reset the association, find the file using Windows Explorer, right-click the file, and then click Open With.  In the Open With dialog box, make sure that the Always use the selected program to open this kind of file check box is selected, and then select Microsoft Word from the Programs list.  If you do not see Microsoft Word in the Programs list, click Browse, and then browse to the location where Microsoft Office is installed.  Click the file named "WINWORD.EXE", and then click Open to select Word and return to the Open With dialog box.  Click OK to associate the file name extension with Word and close the Open With dialog box.