Windows 10 will securely save any passwords for your Wi-Fi networks in a secure location but does not have any way for you as a user to view the saved passwords.
This becomes a problem when you need to retrieve the Wi-Fi password for whatever reason.
However, by using the command prompt or Powershell, the password can be retrieved by using the following command:
netsh wlan show profiles name="NetworkName" key=clear
Change NetworkName to the Wi-Fi network that you have previously connected to.