Dual screen

i am going to tell you that how to setup dual screen on your laptop without installing any extra software.it is simple just follow these steps.
1.plug in your monitor with your laptop
2.right click on your desktop and click properties
3.from tabs above select settings.
4.you will see two monitor icons marked as 1 and 2.
5.now check the box "extend my windows desktop onto this monitor".
6.and you are done, you can change the resolutions of both the monitors according to your need.

its very helpful to use two monitors as u can browse internet or stuff on one,and can do work on the other,especially for coders as you can open visual studio on one monitor and can search internet on the other one...i hope it will help you...