Private Const WM_DEVICECHANGE As Integer = &H219
           Private Const DBT_DEVICEARRIVAL As Integer = &H8000
           Private Const DBT_DEVICEREMOVECOMPLETE = &H8004
           Private Const DBTF_MEDIA = &H1
           Private Const DBT_DEVTYP_VOLUME As UInteger = &H2
 
Private Structure DEV_BROADCAST_HDR
        Public dbch_size As Int32
        Public dbch_devicetype As Int32
        Public dbch_reserved As Int32
End Structure
 
Private Structure DEV_BROADCAST_VOLUME
        Public dbcv_size As Int32
        Public dbcv_devicetype As Int32
        Public dbcv_reserved As Int32
        Public dbcv_unitmask As Int32
        Public dbcv_flags As Int16
End Structure
 
 
Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)
        Select Case m.WParam.ToInt32
            Case DBT_DEVICEARRIVAL
                Dim b As DEV_BROADCAST_HDR
                b = Marshal.PtrToStructure(m.LParam, GetType(DEV_BROADCAST_HDR))
                If b.dbch_devicetype = DBT_DEVTYP_VOLUME Then
                    Dim c As DEV_BROADCAST_VOLUME
                    c = Marshal.PtrToStructure(m.LParam, GetType( _
                      DEV_BROADCAST_VOLUME))
                    If c.dbcv_flags And DBTF_MEDIA Then
                        ListBox1.Items.Add("Drive " + FirstDriveFromMask( _
                          c.dbcv_unitmask) + ": arrived")
                    End If
                End If
            Case DBT_DEVICEREMOVECOMPLETE
                Dim b As DEV_BROADCAST_HDR
                b = Marshal.PtrToStructure(m.LParam, GetType(DEV_BROADCAST_HDR))
                If b.dbch_devicetype = DBT_DEVTYP_VOLUME Then
                    Dim c As DEV_BROADCAST_VOLUME
                    c = Marshal.PtrToStructure(m.LParam, GetType( _
                      DEV_BROADCAST_VOLUME))
                    If c.dbcv_flags And DBTF_MEDIA Then
                        ListBox1.Items.Add("Drive " + FirstDriveFromMask( _
                          c.dbcv_unitmask) + ": goes")
                    End If
                End If
        End Select
        MyBase.WndProc(m)
End Sub
 
Protected Function FirstDriveFromMask(ByVal Unit As Int32) As Char
        Dim Ix As Integer
        For Ix = 1 To 24
            If Unit And Ix Then Exit For
            Unit = Unit >> 1
        Next
        Return Chr(Ix + Asc("A"))
End Function