As bsmasher has pointed out...
Right click on the desktop and go to properites...
Go click on the icon showing monitor 2 and check the box that says this is my main monitor.
Then accept, your taskbar etc should move to your external monitor now and your laptop screen will become your second screen.
It is handy to keep your desktop stretched across two screens so you can see two maximised windows at once - to get a window onto your secondary screen just drag it across into the second screen and when you maximise it there it will maximise within that screen.