Brug af timer sammen med performace counters?

Jeg henter info om hvor meget ledig plads man har på sit c drev. Jeg kunne godt tænke mig at den opdaterede hvert sekund, men synes ikke lige det virker!!

Min kode:

Public Class Form1
    Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "

    Public Sub New()
        MyBase.New()

        'This call is required by the Windows Form Designer.
        InitializeComponent()

        'Add any initialization after the InitializeComponent() call

    End Sub

    'Form overrides dispose to clean up the component list.
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer. 
    'Do not modify it using the code editor.
    Friend WithEvents label1 As System.Windows.Forms.Label
    Friend WithEvents label2 As System.Windows.Forms.Label
    Friend WithEvents PerformanceCounter1 As System.Diagnostics.PerformanceCounter
    Friend WithEvents Timer1 As System.Timers.Timer
    Friend WithEvents PerformanceCounter2 As System.Diagnostics.PerformanceCounter
    Friend WithEvents c As System.Windows.Forms.Label
    Friend WithEvents d As System.Windows.Forms.Label
    Friend WithEvents Button1 As System.Windows.Forms.Button
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.label1 = New System.Windows.Forms.Label
        Me.label2 = New System.Windows.Forms.Label
        Me.c = New System.Windows.Forms.Label
        Me.d = New System.Windows.Forms.Label
        Me.PerformanceCounter1 = New System.Diagnostics.PerformanceCounter
        Me.Timer1 = New System.Timers.Timer
        Me.PerformanceCounter2 = New System.Diagnostics.PerformanceCounter
        Me.Button1 = New System.Windows.Forms.Button
        CType(Me.PerformanceCounter1, System.ComponentModel.ISupportInitialize).BeginInit()
        CType(Me.Timer1, System.ComponentModel.ISupportInitialize).BeginInit()
        CType(Me.PerformanceCounter2, System.ComponentModel.ISupportInitialize).BeginInit()
        Me.SuspendLayout()
        '
        'label1
        '
        Me.label1.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D
        Me.label1.Location = New System.Drawing.Point(16, 24)
        Me.label1.Name = "label1"
        Me.label1.Size = New System.Drawing.Size(80, 16)
        Me.label1.TabIndex = 0
        Me.label1.Text = "Disk space C:"
        '
        'label2
        '
        Me.label2.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D
        Me.label2.Location = New System.Drawing.Point(16, 56)
        Me.label2.Name = "label2"
        Me.label2.Size = New System.Drawing.Size(80, 16)
        Me.label2.TabIndex = 1
        Me.label2.Text = "Disk space D:"
        '
        'c
        '
        Me.c.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D
        Me.c.Location = New System.Drawing.Point(112, 24)
        Me.c.Name = "c"
        Me.c.Size = New System.Drawing.Size(56, 16)
        Me.c.TabIndex = 2
        '
        'd
        '
        Me.d.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D
        Me.d.Location = New System.Drawing.Point(112, 56)
        Me.d.Name = "d"
        Me.d.Size = New System.Drawing.Size(56, 16)
        Me.d.TabIndex = 3
        '
        'PerformanceCounter1
        '
        Me.PerformanceCounter1.CategoryName = "LogicalDisk"
        Me.PerformanceCounter1.CounterName = "% Free Space"
        Me.PerformanceCounter1.InstanceName = "C:"
        '
        'Timer1
        '
        Me.Timer1.AutoReset = False
        Me.Timer1.Enabled = True
        Me.Timer1.Interval = 1000
        Me.Timer1.SynchronizingObject = Me
        '
        'PerformanceCounter2
        '
        Me.PerformanceCounter2.CategoryName = "LogicalDisk"
        Me.PerformanceCounter2.CounterName = "% Free Space"
        Me.PerformanceCounter2.InstanceName = "D:"
        '
        'Button1
        '
        Me.Button1.Location = New System.Drawing.Point(40, 104)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New System.Drawing.Size(88, 32)
        Me.Button1.TabIndex = 4
        Me.Button1.Text = "Button1"
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(292, 266)
        Me.Controls.Add(Me.Button1)
        Me.Controls.Add(Me.d)
        Me.Controls.Add(Me.c)
        Me.Controls.Add(Me.label2)
        Me.Controls.Add(Me.label1)
        Me.Name = "Form1"
        Me.RightToLeft = System.Windows.Forms.RightToLeft.No
        Me.Text = "Form1"
        CType(Me.PerformanceCounter1, System.ComponentModel.ISupportInitialize).EndInit()
        CType(Me.Timer1, System.ComponentModel.ISupportInitialize).EndInit()
        CType(Me.PerformanceCounter2, System.ComponentModel.ISupportInitialize).EndInit()
        Me.ResumeLayout(False)

    End Sub

#End Region


    Private Sub Timer1_Timer(ByVal sender As System.Object, ByVal e As System.Timers.ElapsedEventArgs) Handles Timer1.Elapsed
        c.Text = PerformanceCounter1.RawValue & " mb"
        d.Text = PerformanceCounter2.RawValue & " mb"
    End Sub

End Class