Intel Motherboards : X99E-ITX Mobo doesn't support ECC memory claimed

Thanks so much again for your attention.

 

The ASRock X99E-ITX/AC has only 2 memory slots. They were populated with 2x16GB Corsair non ECC ram which worked. When swapped with 2x16GB Samsung ECC ram (which ASRock claimed on the memory support list as supported), Windows failed to boot normally, only in Safe Mode.

 

Next booting Windows x64 installation DVD, connected onto SATA port (not a USB external DVD drive), Windows x64 for Windows 7, Windows 8 and Windows 10 failed to boot. For Windows 7 it froze with Winlogo & "Starting Windows" . For Win8 and 10, those round wheels the spin on bootup, well they stuck/stop spinning :(

 

I tried pulling all HDD and putting just 1 blank HDD (Samsung 250GB drive formatted but empty) and booting the Windows installation medias, still no luck.

 

As far as I know ECC/non-ECC is a hardware mechanism, transparent to the OS. But certain information is forwarded to the OS such that it appears in Device Manager. I suspect something is buggy there. There is no BSOD or Black Screen, just frozen.

 

And the ASUS X99 board, has identical processor and runs Windows 7 x64, just using memory slots A1 and B1, rest are empty. Both Asrock and Asus machines have Win 7 x64 updated to the latest updates (SP1 and Dec 16 rollup from Microsoft).