The problem is, that Windows is maybe already installed in EFI Mode, im not sure if this is a good idea now, to change this. 
You may need to reinstall Windows then also too, probably you should stick to UEFI then, normally there are enough people around that use EFI,
im actually not sure if this missing Grub entry’s are in relation with a EFI install.
I also created a little gamer guide/overview under Steam, it gives a few points how to make a good transition from Windows to Linux:
Yeah in Energy Settings, i think somewhere under Hibernation under Win10?