Private Sub Button1_Click_1(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) Handles Button1.Click
        Shell("explorer /e, C:\", vbMaximizedFocus)
End Sub

Private Sub Button1_Click_1(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) Handles Button1.Click
        Dim pfad As String
        pfad = "C:\"
        Shell("explorer /e", pfad, vbMaximizedFocus)
End Sub