IIS

Restart IIS

Click Start, click Run type IISReset, and then click OK.

HTTP Header

1. To modify header is not only related to App
2. Server name is not exposer “Microsoft-HTTPAPI/2.0”.
3. Pre-auth was done in the test.
4. The explanation is: If the response's Server header returns Microsoft-HttpApi/2.0, it means that the HTTP.sys is being called, not IIS.
5. Navigate HKLM\SYSTEM\CurrentControlSet\Services\HTTP\Parameters\ If DisableServerHeader doesn't exist, create it (DWORD 32bit) and give it a value of 2. If it does exist, and the value isn't 2, set it to 2
6. Who's that the answer is the ADFS.
7. Registry entry has to be done on the ADFS.
8. It will affect everything
9. It is not IIS hence it does not have to be done on the WAP (reverse proxy)
10. ADFS has to be updated on the registry.
11. to whom response, it can be done.

Resources: https://blogs.msdn.microsoft.com/dsnotes/2017/12/18/wswcf-remove-server-header/