thanks for your thoughts...
fyi...yes i did create two different user accounts. and one user can use outlook express and the other user can use outlook.
but as i discovered from microsoft, you can only have one default email client regardless of how many logins/accounts there are.
if you are interested its a known issue with microsoft. i found out from ms website...
Unable to Set Different E-Mail Programs for Different Users
the issue relates to...
• A mailto: Uniform Resource Identifier (URI).
• Programs that make Messaging Application Programming Interface (MAPI) calls.
• The Send Page by E-Mail command in Internet Explorer.
eg. clicking on a mailto command will fire up the default email client, as only one email client can be set to default, even though the two email programs are being used by the respective users
a little bit more knowledge to tuck away for later use!