NIC Teaming and Powershell Errors

I am attempting to add a new VM Switch and add a NIC Team to it using PowerShell.  I am told this is the only way it can be done.  I have 2 physical Nics installed in the team and the Microsoft Network Adapter Multiplexor Driver is installed. 

I am using the following PowerShell statement:

New-VMSwitch -Name "External Public" -MinimumBandwidthMode Weight -NetAdapterName "Network Team"

The error I get is that the Multiplexor driver is already bound to the Microsoft Virtual Switch Protocol and won't install the NIC's in the team.
Any help would be appreciated

Michael T. Glenn