Is the wireless light on the front of the comp the actual switch?
When you go into Device manager and right click on your wireless card and select properties,then power management, do you see an option to disable to save power? If so dont have it enabled.
Also when you right click it does it say this device is enabled or disabled?
If it installed correctly pressing FN and holding it down while pressing F2 should turn it on, otherwise look around the front of case wer the LEDs are and see if any are a switch or a touch pad to enable it