This has happened to my last 2 laptops. Basically I have plugged a HDMI cable into my laptop and set it to project to second screen. As times gone on, strangely my laptop recognises my HD Television as the PC screen. My laptop monitor is just black like it is turned off, even when the HDMI cable is not plugged in. I've used the windows key + P to go through the options of how to project but it still will only come through my TV. Any help will be appreciated and I apologise if I have not made the issue clear.