How do I completely turn off clam shell mode? I never ever use clam shell mode, as I work with notebooks. I work on the notebook main screen and have external displays attached in my office and at home. I use a Logitech VX Nano mouse with USB receiver always attached. One major annoyance with the (for it's purpose fantastic) clam shell mode is that if the USB mouse is moved while the external display is attached and the notebook is closed, it will start the clam shell mode and will not switch back to the main display.