Please provide me with the support inquiry that you claim so we can help you as much as possible. Now, according to the DX12 support that you are looking for I am afraid that the maximum that the graphics controller supports and will support is DX11 as you can see on the release notes (https://downloadmirror.intel.com/25188/eng/ReleaseNotes_GFX_126.96.36.19952.pdf). The DirectX support is hardware and software dependant and the graphics controller will only support up to DX11 as mentioned before. My apologies for the inconvenience.
Best regards, '
For clarification, the support document number CS-034343 mentioned above includes a footnote for Intel HD 4000 (3rd Generation Graphics) Windows(R) 10 support:
6 Windows 10 drivers for 3rd Generation Intel Core Processors with Intel HD Graphics 4000 and 3rd Generation Intel Core Processors with Intel HD Graphics 2500 (formerly code named Ivy Bridge) will include support for Windows Display Driver Model (WDDM) 1.3.
These drivers are essentially Windows Windows(R) 8.1 drivers that work on Windows(R) 10 in WDDM1.3 mode, not the Windows(R) 10 WDDM2.0 mode, which supports DirectX(R) 12.
Intel graphics support of Windows(R) 10 WDDM2.0 / DirectX(R) 12 begins with the 4th Generation Graphics.