OK guys heres the dilemma. I want to watch NCIS from my laptop on my big screen tv but when I plug the HDMI cable from the TV to the laptop, the screen thats on my laptop is different from the one that is displayed on the TV. Its the same wallpaper but without anything thats on the desktop and I don't know how to switch them or put on the right screen.
That's a feature, not a bug. Some people use more than one monitor. You should be able to drag a window from your laptop to your TV just like you drag a window from place to place on one screen. Alternatively, you could set the TV to mirror the laptop, but you'd then get the lowest resolution of the two on both. You could also turn off the laptop monitor and have the TV be the only active monitor.
Go to "system settings" via the Dash menu and select "Monitors". You can plat with the settings until you find what you want for your particular viewing needs.