Yes, NVIDIA Optimus. Driver versions as reported by inspecting the display adapters in Device Manager : Intel HD Graphics : driver 22.214.171.12400 (26/11/2012) NVIDIA NVS3100M : driver 126.96.36.19900 (18/10/2016)I seem to remember a whole bunch of trouble getting some aspect of the display to work correctly after the 2017 Fall Creators update (not sure why I ended up trying to reinstall one of the drivers - think it was the NVIDIA one), but somehow it did eventually install and work. Not sure why the 1803 update has broken it now. A similar problem with the 1803 update has been reported by someone on the Lenovo forums for a T410 with Intel Graphics. The BIOS contains two relevant options, "Graphics Device" and "OS Detection for NVIDIA Optimus". I left the latter set to "Disabled" (otherwise it would automatically use Optimus if the OS supports it), so I definitely had control via the "Graphics Device" setting. Using the Intel device, or Optimus gave the same result - presumably for both the Intel adapter runs the desktop display, and brightness control is broken (in a similar manner to the report on the Lenovo forum referring to an Intel-only T410). Obviously the Optimus setting should allow the NVIDIA adapter to be used for select applications, as controlled by the NVIDIA utility. Using the NVIDIA device initially resulted in an incorrect display resolution for the LCD after boot (aspect ratio was wrong), but after a little while the system recognised the adapter and the correct 1440x900 resolution appeared. Brightness control worked fine. So, the Intel adapter with the driver I mentioned above is broken under the Windows 10 1803 update. I have not yet tried the driver the Lenovo forum suggests may work.