If you already have a Wifi connection profile on your device then you can display the Password Key for that connection by starting up an Administrator Command Window:
Firstly enter ‘netsh wlan show profiles‘ then press the Enter key, choose the relevant Profile Name.
Then enter ‘netsh wlan show profile ProfileName key=clear‘ then press the Enter key – replacing ProfileName with the one required.
If you get a response ‘The Wireless AutoConfig Service (wlansvc) is not running.’ it could mean you have no Wireless hardware (Wifi Card/dongle/transceiver) on the device.