If you are trying to set up an external monitor and it’s not working, press the Windows logo key + P to make sure that the Extend option is selected. 1 If the Extend option is selected, try the following troubleshooting tips. 1 If you’re not seeing what you expect on the external monitor, start by checking the cable connection. Make sure the cable is securely connected to the video ports on both the computer and the monitor. If you’re using an adapter, make sure it’s securely connected to the cable and the video ports.