I expect when you right-clicked on the file and used the "Open With" context menu item to select "Microsoft Office Word", Windows changed its default File Type association for .DOC files to Microsoft Office Word.
If you had used the Open With > Choose Program
context menu item, you would have been presented with a selection of "Recommended Programs" at the top of its program list. Below the list of programs in the "Open With" window is a check box for telling Windows to always use your selected program for that file extension (.DOC). I expect using that check box would also have achieved the same result as I the method I suggested in my post above (post #2).
Anyway, I'm glad you got it fixed!
Thanks for following up!
I dunno about gremlins. They are a mysterious lot.