For Windows 7 and later versions of the Windows family of operating systems, kernel-mode software must have a digital signature to load on x64-based computer systems. 
The included demo versions of the drivers are signed. But the drivers in Standard and Full sources versions are not signed.

The Microsoft Trusted Root Program no longer supports root certificates that have kernel mode signing capabilities:
https://docs.microsoft.com/en-us/windows-hardware/drivers/install/deprecation-of-software-publisher-certificates-and-commercial-release-certificates 

For the end-user software you have to obtain the Code Signing certificate and sign the driver using Microsoft DevPortal as described here:
https://netfiltersdk.com/help/nfsdk_wfp/signing.html
