In Windows Powershell (as administrator) use the following to create a Windows client L2TP VPN connection and then configure it WITH AES356 and SHA256 encryption:
Add-VpnConnection -Name "MyVPN" -ServerAddress <VPN_WAN_IP> -TunnelType "L2tp"
Set-VpnConnectionIPsecConfiguration -ConnectionName "MyVPN" -AuthenticationTransformConstants SHA196 -CipherTransformConstants AES256 -EncryptionMethod AES256 -IntegrityCheckMethod SHA256 -PfsGroup ECP256 -DHGroup Group14 -PassThru -Force