How do you Use a Laptop as an External Monitor?

How do I use an external monitor while connected to a laptop?

• I am currently using a 15.4 inch laptop. I'm having to stare at a small screen to I bought a 24 inch computer monitor. I have all the necessary cables to make the connection. Everything works, however whenever I open up my laptop to try and cool it off (hot air rises) my external monitor switches back to my laptop screen and stays like that even when I close my laptop. Is there a setting so that this does not happen? My roommate has her laptop connected to an external monitor, however she can open and close her laptop anytime without disturbing anything. Is there a setting somewhere that I can enable to prevent my problem from occurring? Thanks!

• Answer:

  Depending on your operating system and computer, there are various options but the one I would suggest is to not close the lid at all. I believe the mode you are asking for is called clamshell mode. Most laptop systems have a combination key sequence that allows you to choose different types of screen settings. Mine is Fn+F7 which pops up a list of modes, one of which is the choice to only use the external monitor. If that is what you are using currently and it's not working, them look for the control panel for your video card. For instance, nVidia has one that you can access by right clicking on the little nVidia symbol in the tray/pop up windows 7 thing. In mine, there is a monitor setup choice that allows me to configure it all sorts of ways including making the external monitor the only one that is used. I generally keep mine set to have the task bar show on the main monitor and leave the laptop open as a secondary monitor.