There is nothing to fix. The Windows and Linux drivers ignore this (BIOS) setting and dynamically allocate (up to 50% of available memory; 8GB in your case) and deallocate the amount of VRAM available as needs dictate. If you are playing an older game that insists on seeing more VRAM at startup, that's a bug in the game and you need to get an update from the game creators.
Hope this helps,
In more modern CPU Scott is right that the Graphics memory is allocated dynamically (up to 50%), but in case of Intel HD 4600 it is limited to 2048MB only. (but 2048MB is a maximum amount). Note under the Table explains, that the actual amount of maximum graphics memory on your computer can be less than the amounts listed in the table.
So, I suggest that you should address your question to the OEM of your computer/motherboard.
Thanks for the replies. I've noticed that I indeed get up to 2048MB of VRAM (through shared memory), the thing is that it seems I actually get a lot less because games with recommended requirements of 2GB VRAM run very bad on my PC.
Is this 2048MB of VRAM provided by the Intel HD is actually 2048MB?
The reported Shared System Memory is the limit of how much system memory the OS will allow graphics to use at a given time. So, if you see there 2048MB, it is the maximum amount of Graphics Memory available for Intel HD Graphics 4600. If your game runs bad, the reason may be other than lack of memory. Check the setting in this Game and/or ask a question in the Game User forum.
Darn, I thought the dividing line was before that series. Ah well. Too far in the past.
What's important in that case is that the settings for the DRAM (to VRAM) reservation is typically done within the BIOS. I also remember there, in order to support BIOSs that didn't expose these parameters, there was a way to do this via the Registry. Sadly, I do not remember the details for that.
It may be something with my Bios which allows me to allocate no more than 512MB of VRAM to my iGpu. On the other hand it feels like I don't even have 512MB... I think that iGpu are just weak. The low-spec games work fine though, even some of the bigger ones if played with low settings.
Anyway I'm going to play with a dGpu soon so it's not relevant anymore. Thanks for the answers.