I am trying to use OpenID in my website using asp.net_c#. I am working on asp.net forms website with asp.net v4. The issue i am having is with openidselector control from my too
I use the following one and it is really great. But you need to figure out most of the stuff to work with your asp.net logic;
http://code.google.com/p/openid-selector/
EDIT Also this could be helpful;
http://bhaidar.net/post/2011/04/04/OpenID-Single-Sign-On-ASPNET-Web-Forms.aspx