VB .NET USB Eject not working

Form has a ComboBox and a button.

Imports System.IO

Imports System.Management

Imports Shell32

Public Class Form1

Private Sub Form1_Shown(sender As Object, e As EventArgs) Handles Me.Shown

'Dim driveArray() As String = System.IO.Directory.GetLogicalDrives

Dim Drives As DriveInfo() = System.IO.DriveInfo.GetDrives()

For Each d As DriveInfo In Drives

If d.DriveType = DriveType.Removable Then

CBDrives.Items.Add(d.Name)

End If

Next

End Sub

Private Sub Eject(DriveLetter As String)

Dim UsbDrive As String = DriveLetter

Dim ssfDRIVES As Integer = 17

Dim objShell As Object = CreateObject("shell.application")

objShell.NameSpace(ssfDRIVES).ParseName(UsbDrive).InvokeVerb("Eject") 'Exception = 'Object variable or With block variable not set

'powershell(this works)

'$driveEject = New-Object -comObject Shell.Application

'$driveEject.Namespace(17).ParseName("H:").InvokeVerb("Eject")

End Sub

Private Sub BtnEj_Click(sender As Object, e As EventArgs) Handles BtnEj.Click

Eject(CBDrives.Text)

End Sub

End Class