When the user uninstalls the Intel Graphics adapter, Windows automatically switches the primary display to the NVIDIA Graphics adapter. However, the internal LCD panel is driven by the Intel graphics adapter. The user then sees a black screen on the LCD display. This is a limitation of the Operating System that we are working to address with Microsoft.
If this happens, the simplest approach is to reboot the notebook so that Windows can automatically install a VGA driver and display through the internal LCD screen again. The user can instead attempt to connect an external display. Some external displays may be connected to the NVIDIA graphics adapter. However, since this is not true for all Optimus notebook designs, this is not a universal solution. Another option is to VNC or Remote Desktop from another machine assuming the notebook is properly configured.