See my point below about ALPN. You need to advertise support for HTTP&#x2F;2 in the TLS ClientHello and this logic is contained (on a Microsoft platform) in schannel.dll.<p>Microsoft first added ALPN to SChannel in 8.1 and RARELY updates this library outside of OS releases, so that&#x27;s (at least one reason) why you won&#x27;t see on Windows 8&#x2F;2012 Server.