Private Sub Command1_Click()
Dim oAdapters As Object, oAdapter As Object
On Error Resume Next
Set oAdapters = GetObject("winmgmts:").ExecQuery("SELECT * FROM Win32_NetworkAdapterConfiguration WHERE IPEnabled = True")
For Each oAdapter In oAdapters
MsgBox "MAC ADDRESS:  " & Replace(oAdapter.macaddress, ":", " ")
Exit For
Next
End Sub

Option Explicit

Private Sub Command1_Click()
'声明成注释里面的类型应先勾选“工程”-》“引用”里面的“Microsoft WMI Scripting VX.X Library”
On Error Resume Next
Dim sObjTxt As String, oWMINameSpace As Object 'SWbemServices
'Dim ObjSet As SWbemObjectSet, Obj As SWbemObjectEx
Dim ObjSet As Object, Obj As Object
Set oWMINameSpace = GetObject("winmgmts:"): Text1.Text = ""
Set ObjSet = oWMINameSpace.InstancesOf("Win32_NetworkAdapter")
For Each Obj In ObjSet
    sObjTxt = Obj.MACAddress
    If Len(sObjTxt) Then
        Text1.Text = Text1.Text & Obj.Name & vbNewLine & _
                                Obj.MACAddress & vbNewLine
    End If
Next
End Sub