Devi importare il Namespace :

codice:
Imports System.Management
Ti potrei consigliare ad esempio di importare il modello della scheda madre?

codice:
            Dim objManage As String
            Dim oq As New SelectQuery("Win32_ComputerSystem")
            Dim searcher As New ManagementObjectSearcher(oq)
      
            For Each obj As ManagementObject In searcher.[Get]()
                objManage = DirectCast(obj("Model"), String)
                oq = Nothing
                searcher = Nothing
                Dim computerModel  as String = objManage
            Next