When you click on an email link on a webpage, Vista will open the email
program that has been assigned to be the default program for "mailto:"
links. This is normally Windows Mail on a Vista computer.
When you installed Windows Live Mail, it should have taken all of the email
defaults.
Check to see by clicking on
"Start" - "Default Programs" - "Set your default programs"
highlight "Windows Live Mail", then click on "Choose defaults for this
program".
click on "Select all" to make sure the MAILTO is selected
click on "Save"