Methods and apparatus to operate closed-lid portable computers are disclosed. An example apparatus includes a camera input analyzer to analyze image data captured by a world facing camera on a portable computer when a lid of the portable computer is in a closed position. The world facing camera is on a first side of the lid. The portable computer includes a primary display on a second side of the lid opposite the first side. The example apparatus further includes a secondary display controller to render content via a secondary display of the portable computer in response to the analysis of the image data. The secondary display controller is to render the content on the secondary display while the lid of the portable computer is in the closed position and the primary display is turned off.