Hypertext Transfer Protocol Version 2 (HTTP/2)
This specification describes an optimized expression of the semantics of the Hypertext Transfer Protocol (HTTP), referred to as HTTP version 2 (HTTP/2). HTTP/2 enables a more efficient use of network resources and a reduced perception of latency by introducing header field compression and allowing multiple concurrent exchanges on the same connection. It also introduces unsolicited push of representations from servers to clients.
This specification is an alternative to, but does not obsolete, the HTTP/1.1 message syntax. HTTP's existing semantics remain unchanged.
As many browsers are not compatible with HTTP/2 message syntax, the below attached registry file once run on your system will disable HTTP/2 and you can further use Attachments.expert of IIS version 10 with HTTP/1.1