I've heard different things. Seems like Microsoft experimented with a beta service, but I don't know if it's still available, or ever made it into production.
If Windows Live ID is an OpenID Provider, where is the endpoint?
No. Windows Live ID is not an OpenID Provider. They use a proprietary protocol. Ever since the close of their "beta" period, they've never announced plans to continue with it.
toddm
Check out this, I believe they use OAuth (not OpenID).
Looks like it really hasn't made it into production.
来源：https://stackoverflow.com/questions/4056263/is-windows-live-id-an-openid-provider