Hi Ken
When you are not able to open up a particular file even
when you know the required application is installed on
your machine, all you need to do is follow these simple
steps.
1) Click once on the respective file(in your case directly
in the Outlook message).
2) Hold the Shift key down on your keyboard and right
click on the respective file.
3) From the menu displayed choose Open With... which
launches a Open with window(this could take a few seconds).
4) Choose the appropirate application to open the file, in
your case Excel.(If the application required is not listed
you can find it using the Browse button).
Hope this helps.
Regards
Manoj M. M.