Default mail client

Go to Control Panel->Internet Options->Programs, and under E-mail, make sure your email application is selected. If you're using web-based email, then you need to check w/ that provider about how to add it to that list. For example, I know Yahoo email requires installation of their toolbar. Now Yahoo will appear as an email option within that list. Although I haven’t checked them all, I suspect other web-based email services have similar requirements.