This probably is a bug in AHII and AHII ? I don't know, I only have two other games installed, X-plane and DCS, and this is no problem with those two.
Lots of laptops (maybe also desktop ?) have hybride display adapters. There is one general for everyday use (Intel integrated graphics in my case) and a 3D card used only for rendering (Nvidia 960M in my case). By default the settings are in "automatic", which means the software decides if the 3D card is to be used. This works fine with X-plane and DCS, but NOT for AHII or AHIII.
In AHII/III the intel graphics card is chosen by default, and there is no option to select Nvidia (on the splash screen settings). Then AH simply ise Intel graphics, and the FR is abyssmal. To change this I have to open the NVidia control panel and change it from auto to NVidia in the global settings, or change it even "more manually" in the "program settings" tab. Both methods work.
Only when doing that will AHII/III show NVidia graphics card in the splash screen. Then FR goes from abysmal to 60 and above (depending on actual settings in the game of course).
A bug? X-plane and DCS have no problem selecting the correct adapter, so it probably is.