Error opening Excel Files
 

I have Office 2007 installed on my notebook. Everything functions as normal
except if I try to open an excel file by double-clicking it in explorer, or
by double-clicking and excel file as an e-mail attachment. I always get the
following error message:
C:\users\me\appdata\local\temp\filename.xls could not be opened, because the
associated helper application does not exist. Change the association in your
preferences.

Anybody have any idea on how to fix this?