If you go to nVidia control Panel, it should offer you to adjust brightness appropriately. This brightness problem generally happens due to nVidia who takes control of Windows brightness setting from Windows' default display adapter.
E for Excel, unfortunately, my NVIDIA card has no control over my display's brightness. It is the secondary discrete card, and so the NVIDIA control panel only offers me DirectX, OpenGL, and PhysX-related settings - nothing relating to my actual display hardware. I have also checked the Intel GPU settings, for good measure, and it also lacks a brightness control tool. I think this issue is related more to the way Windows itself gives a percentage abstraction over top of actual display brightness levels used by the laptop hardware, and the minimum setting is simply too high for my liking. Thank you for your suggestion, though.