Consider the following scenario:
- Yo have installed server-core server and it only has a physical NIC
- You created a external virtual network (VSwitch) and configured VLAN tag as well
- You realized that you are being disconnected because your client computer is not in that VLAN

You want to know how to remove the VLAN tag when no one is able to connect to the server remotely?

說明與方法︰
附件的 Script 可以移除 Hyper-V Server-core 上的所有 Virtual Networks 然後還原實體 NICs 的 Binding.

*** This script  is provided "AS IS" with no warranties, and confers no rights. You assume all risk for your use ***

/*
Copyright (c) Microsoft Corporation
Module Name:
    nvspscrub.js
*/

//
// VirtualSwitchManagementService object.  Logical wrapper class for Switch Management Service
//
function
VirtualSwitchManagementService(
    Server,
    User,
    Password
    )
{
    //
    // Define instance fields.
    //   
    this.m_VirtualizationNamespace  = null;
    this.m_VirtualSwitchManagementService = null;

    //
    // Instance methods
    //       
    VirtualSwitchManagementService.prototype.DeleteSwitch =
    function(
        VirtualSwitch
        )
    /*++

    Description:

        Deletes a virtual switch
    Arguments:

        VirtualSwitch - Msvm_VirtualSwitch object to delete

    Return Value:

        SWbemMethod.OutParameters object.

    --*/
    {
        var methodName = "DeleteSwitch";

        var inParams = this.m_VirtualSwitchManagementService.Methods_(methodName).inParameters.SpawnInstance_();

        inParams.VirtualSwitch = VirtualSwitch.Path_.Path;
        return this.m_VirtualSwitchManagementService.ExecMethod_(methodName, inParams);
    }
    VirtualSwitchManagementService.prototype.DeleteInternalEthernetPort =
    function(
        InternalEthernetPort
        )

    /*++

    Description:

        Deletes an internal ethernet port
    Arguments:

        InternalEthernetPort - Msvm_InternalEthernetPort to delete
    Return Value:

        SWbemMethod.OutParameters object.

    --*/

    {
        var methodName = "DeleteInternalEthernetPort";

        var inParams = this.m_VirtualSwitchManagementService.Methods_(methodName).inParameters.SpawnInstance_();
        inParams.InternalEthernetPort = InternalEthernetPort.Path_.Path;
        return this.m_VirtualSwitchManagementService.ExecMethod_(methodName, inParams);
    }
    VirtualSwitchManagementService.prototype.UnbindExternalEthernetPort =
    function(
        ExternalEthernetPort
        )

    /*++

    Description:

        Unbinds an external ethernet port from the virtual network subsystem.  Usually this method
         won't be called directly
    Arguments:

        SwitchPort - Msvm_ExternalEthernetPort to unbind.

    Return Value:

        SWbemMethod.OutParameters object.

    --*/

    {
        var methodName = "UnbindExternalEthernetPort";

        var inParams = this.m_VirtualSwitchManagementService.Methods_(methodName).inParameters.SpawnInstance_();

        inParams.ExternalEthernetPort = ExternalEthernetPort.Path_.Path;
        return this.m_VirtualSwitchManagementService.ExecMethod_(methodName, inParams);
    }
    //
    // Utility functions
    //
    VirtualSwitchManagementService.prototype.WaitForNetworkJob =
    function(
        OutParams
        )

    /*++

    Description:

        WMI calls will exit with some type of return result.  Some will require
        a little more processing before they are complete. This handles those
        states after a wmi call.

    Arguments:

        OutParams - the parameters returned by the wmi call.

    Return Value:

        Status code

    --*/

    {
        if (OutParams.ReturnValue == 4096)
        {
            var jobStateStarting        = 3;
            var jobStateRunning         = 4;
            var jobStateCompleted       = 7;
            var networkJob;

            do
            {
                WScript.Sleep(1000);
                networkJob = this.m_VirtualizationNamespace.Get(OutParams.Job);

            } while ((networkJob.JobState == jobStateStarting) ||
                     (networkJob.JobState == jobStateRunning));

            if (networkJob.JobState != jobStateCompleted)
            {
                throw(new Error(networkJob.ErrorCode,
                                networkJob.Description + " failed: " + networkJob.ErrorDescription));
            }
            return networkJob.ErrorCode;
        }

        return OutParams.ReturnValue;
    }
    VirtualSwitchManagementService.prototype.GetSingleObject =
    function(
        SWbemObjectSet
        )

    /*++

    Description:

        Takes a SWbemObjectSet which is expected to have one object and returns the object

    Arguments:

        SWbemObjectSet - The set.

    Return Value:

        The lone member of the set.  Exception thrown if Count does not equal 1.

    --*/

    {
        if (SWbemObjectSet.Count != 1)
        {
            throw(new Error(5, "SWbemObjectSet was expected to have one item but actually had " + SWbemObjectSet.Count));
        }
        return SWbemObjectSet.ItemIndex(0);
    }

    //
    // Aggregate functions
    //
    VirtualSwitchManagementService.prototype.DeleteSwitchAndWait =
    function(
        VirtualSwitch
        )
    /*++

    Description:

        Deletes a switch
    Arguments:

        VirtualSwitch - Msvm_VirtualSwitch to delete
    Return Value:
        None.

    --*/
    {
        var outParams = this.DeleteSwitch(VirtualSwitch);

        var wmiRetValue = this.WaitForNetworkJob(outParams);

        if (wmiRetValue != 0)
        {
            throw(new Error(wmiRetValue, "DeleteSwitch failed"));
        }
    }
    VirtualSwitchManagementService.prototype.DeleteInternalEthernetPortAndWait =
    function(
        InternalEthernetPort
        )
    /*++

    Description:

        Deletes an internal ethernet port
    Arguments:

        InternalEthernetPort - Msvm_InternalEthernetPort to delete
    Return Value:

        SWbemMethod.OutParameters object.

    --*/
    {
        var outParams = this.DeleteInternalEthernetPort(InternalEthernetPort);

        var wmiRetValue = this.WaitForNetworkJob(outParams);

        if (wmiRetValue != 0)
        {
            throw(new Error(wmiRetValue, "DeleteInternalEthernetPortAndWait failed"));
        }
    }
    VirtualSwitchManagementService.prototype.UnbindExternalEthernetPortAndWait =
    function(
        ExternalEthernetPort
        )
    /*++

    Description:

        unbinds an internal ethernet port
    Arguments:

        ExternalEthernetPort - Msvm_ExternalEthernetPort to unbind
    Return Value:

        SWbemMethod.OutParameters object.

    --*/
    {
        var outParams = this.UnbindExternalEthernetPort(ExternalEthernetPort);

        var wmiRetValue = this.WaitForNetworkJob(outParams);

        if (wmiRetValue != 0)
        {
            throw(new Error(wmiRetValue, "UnbindExternalEthernetPortAndWait failed"));
        }
    }
    //
    // Constructor code
    //
    if (Server == null)
    {
        Server = WScript.CreateObject("WScript.Network").ComputerName;
    }
    //
    // Set Namespace fields
    //
    try
    {
        var locator = new ActiveXObject("WbemScripting.SWbemLocator");

        this.m_VirtualizationNamespace = locator.ConnectServer(Server, "root\\virtualization", User, Password);
    }
    catch (e)
    {
        this.m_VirtualizationNamespace = null;
        throw(new Error("Unable to get an instance of Virtualization namespace: " + e.description));
    }
    //
    // Set Msvm_VirtualSwitchManagementService field
    //
    try
    {
        var physicalComputerSystem =
                this.m_VirtualizationNamespace.Get(
                        "Msvm_ComputerSystem.CreationClassName='Msvm_ComputerSystem',Name='" + Server + "'");
        this.m_VirtualSwitchManagementService = this.GetSingleObject(
                                                        physicalComputerSystem.Associators_(
                                                            "Msvm_HostedService",
                                                            "Msvm_VirtualSwitchManagementService",
                                                            "Dependent"));
    }
    catch (e)
    {
        this.m_VirtualSwitchManagementService = null;
        throw(new Error("Unable to get an instance of Msvm_VirtualSwitchManagementService: " + e.description));
    }
}

//
// main
//

var wshShell = WScript.CreateObject("WScript.Shell");

var g_NvspWmi   = null;

Main();

function Main()
{
    WScript.Echo("Looking for nvspwmi...");
    g_NvspWmi   = new VirtualSwitchManagementService();

    WScript.Echo("");
    WScript.Echo("Looking for internal (host) virtual nics...");
    var list = g_NvspWmi.m_VirtualizationNamespace.ExecQuery("SELECT * FROM Msvm_InternalEthernetPort");
    for (i = 0; i < list.Count; i++)
    {
        var next = list.ItemIndex(i);
        WScript.echo(next.DeviceID);
        g_NvspWmi.DeleteInternalEthernetPortAndWait(next);
    }
    WScript.Echo("");
    WScript.Echo("Looking for switches...");
    list = g_NvspWmi.m_VirtualizationNamespace.ExecQuery("SELECT * FROM Msvm_VirtualSwitch");
    for (i = 0; i < list.Count; i++)
    {
        var next = list.ItemIndex(i);
        WScript.echo(next.Name);
        g_NvspWmi.DeleteSwitchAndWait(next);
    }
    WScript.Echo("");
    WScript.Echo("Looking for external nics...");
    list = g_NvspWmi.m_VirtualizationNamespace.ExecQuery("SELECT * FROM Msvm_ExternalEthernetPort WHERE IsBound=TRUE");
    for (i = 0; i < list.Count; i++)
    {
        var next = list.ItemIndex(i);
        WScript.echo(next.DeviceID);
        g_NvspWmi.UnbindExternalEthernetPortAndWait(next);
    }
    WScript.Echo("");
    WScript.Echo("Finished!");
}