Imports System.Management

Public Class Form1
  Public Function GetDiskSpace(ByVal drive As String) _
        As System.UInt64
    Dim diskClass As New ManagementClass("Win32_LogicalDisk")
    Dim disks As ManagementObjectCollection = _
          diskClass.GetInstances()
    Dim disk As ManagementObject
    Dim space As System.UInt64

    drive = drive.ToUpper.Substring(0, 2)

    For Each disk In disks
      If CStr(disk("Name")) = drive Then
        space = CType(disk("FreeSpace"), System.UInt64)
      End If
    Next disk
    Return space
  End Function

  Private Sub Form1_Load(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles MyBase.Load
    ListBox1.DataSource = Environment.GetLogicalDrives()
  End Sub

  Private Sub ListBox1_SelectedIndexChanged(ByVal sender As _
        System.Object, ByVal e As System.EventArgs) Handles _
        ListBox1.SelectedIndexChanged
    Dim b, kb, mb, gb As Double

    Label1.Text = "Bitte warten..."
    Label2.Text = ""
    Label3.Text = ""
    Label4.Text = ""
    Label5.text = ""
    Label1.Refresh()
    Label2.Refresh()
    Label3.Refresh()
    Label4.Refresh()
    Label5.Refresh()

    Cursor.Current = Cursors.WaitCursor()

    b = CDbl((GetDiskSpace( _
          ListBox1.SelectedItem.ToString)).ToString)

    kb = b * 1 / 1024
    mb = b * 1 / 1048576
    gb = b * 1 / 1073741824

    Label1.Text = b.ToString("n") & " Byte"
    Label2.Text = kb.ToString("f3") & " KiloByte"
    Label3.Text = mb.ToString("f3") & " MegaByte"
    Label4.Text = gb.ToString("f3") & " GigaByte"
    Label5.Text = "Freier Platz auf Laufwerk " & _
          ListBox1.SelectedItem.ToString

    Cursor.Current = Cursors.Default()
  End Sub

  Private Sub Button1_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles Button1.Click
    Me.Close()
  End Sub
End Class