Question ManagementEventWatcher Start "not supported" error

[jp26198926]

hello guys..

i am trying to detect the plug/unplug of usb flashdrive using WMI
but i get an error message "Not Supported";

here is my code:

Imports System.Management

Public Class Form1
    Private WithEvents m_MediaConnectWatcher As New ManagementEventWatcher
    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Dim query2 As New WqlEventQuery("SELECT * FROM __InstanceOperationEvent WITHIN 1 " _
         & "WHERE TargetInstance ISA 'Win32_DiskDrive'")
        m_MediaConnectWatcher = New ManagementEventWatcher
        m_MediaConnectWatcher.Query = query2
        m_MediaConnectWatcher.Options.Timeout = New TimeSpan(1000)
        [COLOR=red]m_MediaConnectWatcher.Start()[/COLOR]
    End Sub
End Class

the error is on the line with red text

that code works fine on my workpace machine with vista OS
but here in home im using xp sp3 which the code not working.

thnx in advance.