Find WIFI password via Control Panel

The WiFi Status box will open. Click on the Properties button to open the Wireless Network Properties box. Here under the Security tab, select the Show characters check-box. The password will be visible against the Network security key column.

Find Wi-Fi password with Command prompt

netsh wlan show profile name=YOURWIFINAME key=clear  
YOURWIFINAME =  your wireless SSID  
You will then be able to see the WiFi password under Security settings > Key Content