I have been watching the cricket on Chromecast but have noticed that when I have both screens running - the laptop and the TV - that it stutters. Sometimes a small window comes up allowing me to close the window on the laptop. But what happens if that small window does not come up? The TV is almost unwatchable until we close the window on the laptop. But how do we close the window on the laptop if that small "close laptop window" does not appear? Is there some other way of closing the laptop window?

Thanks for your help.