Hi, John.

>I need to implement my desktop and internet application to have single sign on feature. IOW, once user login to either desktop or ASP.NET application succesfully, then no login required for user to access the another application.

You can't do it directly, as you usually log into sessions, and both platforms has different sessions, unless you run destop apps from the web site or log into the website from within the desktop app.

Maybe if you describe your use case in more detail we can help.

Best luck,