OK so I've just installed this driver (finally) and there is a bug in windows 8.1 when you open the HD graphics panel and you click on "Video".
The application then starts hanging and I'm forced to close it.
How could I fix that?
(I already cleaned my previous Intel graphics drivers with Display Driver Uninstaller)
thank you again.
Release date is definitely January 2018.
Regarding the issue:
Run msinfo32.exe and check "Windows error reporting" for entries that refer to Intel components.
Also check for errors in event viewer as described at How to View the System Log in Event Viewer
Otherwise update .NET which is used by the control panel
Thanks for your infos but in fact an old version of the driver automatically installed itself (from windows) so this issue was not from the latest Intel 2018 driver.
Now I managed to install the good version of the driver and all is (almost) fine. (I have a small known bug in the Intel Panel : Bug: Windows region settings (digit grouping symbol, decimal symbol) break Intel HD Graphics Control Panel but i can change the settings in this panel so it's OK)