Why black looks gray using Intel HD Graphics drivers on Z3735F and z3770?

[EPerr2]

I've noticed a strange behaviour using the intel drivers. Below you can see two picture of the same tablet connected via hdmi to an external monitor: the first one with the Intel HD Graphics driver, the second one with the Microsoft Basic Display driver. In the first image black is gray. I tried to decrease the brightness and the gamma in the intel panel and in the windows color calibration tool, I also tried to downgrade the drivers, but nothing seems to work.

(edit: dxdiag attached)

[EPerr2]

Solved using regedit

1) Go to the "display" registry key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Contro l\Class\{4D36E968-E325-11CE-BFC1-08002BE10318}\****

2) Create DWORD value:

EnableRGBFullRange

and set it to 1

3) Reboot.

[SMurp5]

Thanks I will give it a try and see what is best to do