have office 2003, how to make office outlook exp default email

trying to eliminate a step by having outlook express my default email..when
using word etc. wanting to send to email recipient, my office 2003 defaults
to "outlook."
i have everything in outlook express and would like not to have to go thru
the extra step of "insert attachment" in outlook express.

have tried to make outlook express my default email by going to
tools,internet options,programs, Email drop down box..the email drop down box
only has options for Microsoft outlook and yahoo...nothing for "express."
Have also tried going to Outlook express, tools, options, and clicking "make
this default," but it is greyed out and cannot click on it...suggestions??