Open command prompt, and run it as an administrator.
Then, type the following command:

					netsh wlan show profile

 To reveal the password of a specific network, type the following command, substituting “NETWORK NAME” with the Wi-Fi network you’re looking up:

					netsh wlan show profile “NETWORK NAME” key=clear


All Wifi password in Windows 10
For all WiFi password in Windows 10 use powershell in administrator, and use the following command:

					(netsh wlan show profiles) | Select-String “\:(.+)$” | %{$name=$_.Matches.Groups[1].Value.Trim(); $_} | %{(netsh wlan show profile name=”$name” key=clear)} | Select-String “Key Content\W+\:(.+)$” | %{$pass=$_.Matches.Groups[1].Value.Trim(); $_} | %{[PSCustomObject]@{ PROFILE_NAME=$name;PASSWORD=$pass }} | Format-Table -AutoSize