open up device manager and check to see if its detecting a network controller with a red X on it, indicating that there isn't a driver for it.
if you do see that and still can't install the diver, try a different driver.
if you don't see the above then:
if you have some sort of function key combo to enable/disable wireless make sure its enabled. if you have some sort of wireless on/off toggle switch on your laptop, make sure it in the on position.