0 Physical devices found - Vulkan Chopper Demo

Hi, there. I’m a developer. This my enviroment: NVIDIA GeForce 820M GPU, Intel Core I5 CPU, Windows 10 OS.

I installed the drivers for vulkan from https://developer.nvidia.com/vulkan-driver.
And I installed the LunarG SDK, for testing i download NVIDIA Chopper Demo. I run it, but it says 0 Physical Devices found. I have two 2 GPU (Discrete and Integrated). What is the problem?

I know meaning of this vkEnumeratePhysicalDevices assign GPU_Count variable 0. And this means i do not have any Vulkan capable GPU. But i have.