Adding another email client to the default screen

[Big_Mack1]

I use Yahoo as my email client, yet Vista doesn't even show it (on the
drop-down menu) as one of my possible selections when selecting a default
email program. All the drop-down shows is (surprise...) Windows Mail...

How do I force Vista to list Yahoo as a possible selection when I go to the
"Set Default Programs" page?

Can you give me the system folder or registry location (that the drop-down
menu uses) so that I can add Yahoo to the list in order to select it from the
"Default Programs" Page?

Thanks

 

[Not Me]

Usually while installing the Yahoo messenger or Yahoo toolbar for IE, it
gives you the option to add Yahoo Browser Services.
If it isn't installed, Yahoo can't be the default email handler.