After the system update (I believe in February), I first noticed errors in Device Manager for Surface Keyboard Backlight and Surface Pen Pairing - both indicate that "This device is not working properly because Windows cannot load the drivers required for this device. (Code 31)". I ran (more than once) the Windows Hardware Troubleshooting and (each time) it indicates that there are problems with the drivers and that reinstalling might fix the problems. However, despite letting it reinstall the drivers and then rebooting, the errors don't go away. I also tried uninstalling the Surface Pen Pairing and then letting Windows detect it again. After doing so, I was still able to pair the pen, but the error persists. I was hoping the next system update (April) might make the errors go away, but it did not. Short of a clean (Windows 10 Pro) reinstall, does anyone have any suggestions? Thanks. P.S. Both the keyboard lighting and the pen seem to work correctly, so I guess I would consider this problem as more of an irritant than anything else.