I have solved the issue as to why its working only in Windows 10, its due to the fact that the demo relies on D3D11.1 which according to the code is only activated when the operating system of the user matches Windows 10. Meaning users of Windows 8 and below won’t have the AllowedFeatureLevel set to 11.1 meaning the demo won’t work. If you want to change this, open WindowsD3D11Device.cpp and go to line 97 and change the windows version.
I dont know what’ll happen when running on Windows 8 or 7. So do this at your own risk.