Private Function IsWLANInterfaceAvailable() As Boolean
        Dim wql As String = Nothing
        Dim searcher As ManagementObjectSearcher = Nothing
        Dim mc As ManagementObjectCollection = Nothing
        Try
            wql = "SELECT * FROM MSNdis_80211_ReceivedSignalStrength WHERE" & _
              "active = true"
            searcher = New ManagementObjectSearcher("root\WMI", wql)
            mc = searcher.Get()
            If mc Is Nothing Then Return False
            Return CType(mc.Count, Boolean)
        Catch ex As System.Management.ManagementException
            Debug.WriteLine("Errorcode: " + ex.ErrorCode.ToString())
            Return False
        Finally
            searcher.Dispose()
        End Try
    End Function

 
        If Me.IsWLANInterfaceAvailable Then
            '// ok
            Me.errorIcon.Icon = New Icon("ok.ico")
        Else
            '// not available
            Me.errorIcon.Icon = New Icon("error.ico")
        End If