Well... you're asking in the wrong place (a newsgroup for Microsoft Access
databases) but try this:

Select "My Computer" from the Start button.
Select Tools... Folder Options.
Select the tab "File Types".
Scroll down to the .Doc extension (or any other extension that's been
hijacked).
Click the "Change" button and choose Word (if that's what you want to use as
the default program for this type of file).

            John W. Vinson [MVP]