title: How to implement Windows Authentication with IdentityServer 4
body: <p>How to correctly implement Windows Authentication with Identity Server 4?
  Are there any samples to do that?</p>
  <p>I looked at the source code of IdentityServer 4, and in the Host project in the AccountController, I noticed that there is Windows Authentication checks and they are implemented as an External Provider, but I can't seem to work out the configuration.</p>
  <p>Has anybody successfully implemented windows authentication with idsrv4 and how?</p>