AniChatt :
It is simply because you don't need the integrated gpu any more as you have installed a discrete gpu. It may create some conflict with drivers. So many mobo manufacturers introduce this feature in their board to isolate this issue. It is not a fault and it is as per design. Always plug your monitor in the dgpus port. just ignore the igpu. What is your problem?
my real problem is why im asking this is... when I still have no gpu my other games like dark souls 3 and nier:automata never crash and is running in a smooth 25-40 fps depending on their location, but its not enough for me. So when I got a gpu my performance has increased massively but in the cause of random system crash, freezing (this doesn't affect the other games, only nier:automata and dark souls 3 are crashing randomly(settings the lightning to low in ds3 didn't help)) I'm not really expert in computer things but I think that If i use the integrated graphics card while the gpu is present then the crashing will stop..... well if I'm wrong then I have no choice but to buy a better gpu.