Tricky if you have Word installed. Windows will have registered word.exe
associated with the .doc file extension. You 'could' change the association
for .doc so that it opens the Word Reader but that will cause even more
problems because when you open Word it will run the Office Installer to
reregister .doc as the default which takes around a minute to complete.
But I expect that it may be possible to add the Open With command to the
right-click shortcut in Outlook. This would let you right-click the
attachment, select Open With, Word Viewer. That is a question I would ask in
an Outlook Newsgroup.
Terry