Maybe this could help you. I found it in this post
you might look at this it explains about it.
http://social.technet.microsoft.com/wiki/contents/articles/4656.wpf-application-with-live-id-facebook-google-yahoo-open-id.aspx
First of all try the link I m sending you ... It will provide you the basic structure of how to setup your live ID : MSDN blog
You can also try this one to read more : MSDN library