Okay thank you very much for helping me :)

After resetting,windows used the microsoft basic display and then i installed the 5500 driver which i downloaded from intel website,,and then it works fine after some reboot the gt840m drivers is...

In windows 10 sections,there are no nvidia drivers but in windows 8.1 sections there is available so is it okay if i download from windows 8.1 sections ?

It's nvidia geforce gt840m

Okay i think i solved this by resetting windows,,but i lost all of my apps:'(
Then i installed the intel hd drivers and it works normally...
But i still in afraid to install nvidia drivers because...

Still,i can't boot into windows,,so i should update the display driver,right ?

Okay,thank you...
I have 2 display graphics options i've done as you said and i removed the nvidia display graphics but it still like before so should i uninstall the microsoft basic display driver ?

Hey i've just updated my asus a555ln laptop from win 8.1 to win 10...
Everything went nice with drivers automatically installed but the display drivers is lost.
So i've installed the intel hd...