Imports System.Management
Public Class Form1

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim fso As Object
        Dim dc As Object
        Dim d As Object
        Dim xx As String
        fso = CreateObject("Scripting.FileSystemObject")
        dc = fso.Drives
        For Each d In dc
            xx = d.DriveLetter
        Next

        Me.TextBox2.Text = GetSerialNumber(xx & ":")

    End Sub
    Public Function GetSerialNumber(ByVal DriveLetter As String) As String
        DriveLetter = Mid$(DriveLetter, 1, 2)
        If Mid$(DriveLetter, 2, 1) <> ":" Then Return ""

        Dim wmi_ld, wmi_dp, wmi_dd As ManagementObject
        Dim temp, parts(), ans As String

        ans = ""
        ' get the Logical Disk for that drive letter 
        wmi_ld = New ManagementObject("Win32_LogicalDisk.DeviceID='" & _
         DriveLetter.TrimEnd("\"c) & "'")
        ' get the associated DiskPartition  
        For Each wmi_dp In wmi_ld.GetRelated("Win32_DiskPartition")
            ' get the associated DiskDrive 
            For Each wmi_dd In wmi_dp.GetRelated("Win32_DiskDrive")
                ' There is a bug in WinVista that corrupts some of the fields 
                ' of the Win32_DiskDrive class if you instantiate the class via 
                ' its primary key (as in the example above) and the device is 
                ' a USB disk. Oh well... so we have go thru this extra step 
                Dim wmi As New ManagementClass("Win32_DiskDrive")
                ' loop thru all of the instances. This is silly, we shouldn't 
                ' have to loop thru them all, when we know which one we want. 
                For Each obj As ManagementObject In wmi.GetInstances
                    ' do the DeviceID fields match? 
                    If obj("DeviceID").ToString = wmi_dd("DeviceID").ToString Then
                        ' the serial number is embedded in the PnPDeviceID 
                        temp = obj("PnPDeviceID").ToString
                        If Not temp.StartsWith("USBSTOR") Then
                            MessageBox.Show(DriveLetter & " doesn't appear to be USB Device", "Error")
                            Return ""
                        End If
                        parts = temp.Split("\&".ToCharArray)
                        ' The serial number should be the next to the last element 
                        ans = parts(parts.Length - 2)
                    End If
                Next
            Next
        Next

        Return ans
    End Function


End Class