To tell if your wireless network card is on and enabled look down on the system tray for the following symbol. 
 

 

 

If the wireless card is off and disabled it will display the following symbol.

 

 

Wireless network cards can be turned on and off on the laptops by keystroke combination of with a physical switch.

The class systems use a keystroke combination to turn the wireless card on and off. You must press Fn + the F2 to turn on or off.

 

 

· On Latitude Class systems such as the E5400, E5410, E5420 and the E5530 the wireless is controlled by a physical switch.