Mac Forum / Applications / MS Office / December 2007

Try this:

in the Finder, select a Word or Excel document, then press Command
(Apple) + i to bring up the Info window. Expand the Open with section of
that window and select the appropriate application from the dropdown
list. If Word or Excel are not visible, choose Other and navigate to the
 application. After selecting the correct application, click on Change
All, then check if the application now launches correctly.

Also: when you installed Office on your new Mac Mini, did you make sure
to remove the Test Drive version that came with your computer? The Test
Drive is known to cause problems, and if your problem does not go away,
it might be a good idea to remove Office and the Test Drive and to
reinstall Office afterwards. To remove Office properly, go to
Applications/Microsoft Office 2004/Additional Tools/Remove Office and
drag the Remove Office application to your desktop. Run it from there,
then delete the Microsoft Office 2004 in your Applications folder and
proceed with the reinstall.

PLEASE don't post the same message in multiple newsgroups - it just
tends to fragment your answers, and wastes the time of those answering
questions that have already been answered.

For each problem file type (.xsl., .doc, etc.) do this:

1. In the Finder, select (highlight) one of the problem files of that
type.
2. From the Finder menu bar, select File > Get Info.
3. In the Info window, in the Open With group, select the appropriate
Microsoft Office application that should open the file.
4. Click Change All.