Como añadir una marca de agua en una imagen usando la librería Aspose Imaging ( http://www.aspose.com/.net/imaging-component.aspx ).

    ' Add Watermark
    ' By Elektro
 
    ''' <summary>
    ''' Adds a watermark into an image, at the specified position.
    ''' </summary>
    ''' <param name="img">Indicates the image.</param>
    ''' <param name="text">Indicates the watermark text.</param>
    ''' <param name="fnt">Indicates the watermark text font.</param>
    ''' <param name="color">Indicates the watermark text color.</param>
    ''' <param name="position">Indicates the watermark text position.</param>
    ''' <returns>Aspose.Imaging.Image.</returns>
    Private Function AddWatermark(ByVal img As Aspose.Imaging.Image,
                                  ByVal text As String,
                                  ByVal fnt As Aspose.Imaging.Font,
                                  ByVal color As Aspose.Imaging.Color,
                                  ByVal position As Aspose.Imaging.PointF) As Aspose.Imaging.Image
 
        Using brush As New Aspose.Imaging.Brushes.SolidBrush With {.Color = color, .Opacity = 100.0F}
 
            ' Create and initialize an instance of Graphics class.
            Dim g As New Aspose.Imaging.Graphics(img)
 
            ' Draw a String using the SolidBrush object and Font, at specific Point and with specific format.
            g.DrawString(s:=text, font:=fnt, brush:=brush, point:=position)
 
        End Using
 
        ' Return the modified image.
        Return img
 
    End Function
 
    ''' <summary>
    ''' Adds a watermark into an image, at a prefedined position.
    ''' </summary>
    ''' <param name="img">Indicates the image.</param>
    ''' <param name="text">Indicates the watermark text.</param>
    ''' <param name="fnt">Indicates the watermark text font.</param>
    ''' <param name="color">Indicates the watermark text color.</param>
    ''' <param name="position">Indicates the watermark text position.</param>
    ''' <param name="verticalmargin">Indicates the watermark text vertical margin.</param>
    ''' <param name="horizontalmargin">Indicates the watermark text horizontal margin.</param>
    ''' <returns>Aspose.Imaging.Image.</returns>
    Private Function AddWatermark(ByVal img As Aspose.Imaging.Image,
                                  ByVal text As String,
                                  ByVal fnt As Aspose.Imaging.Font,
                                  ByVal color As Aspose.Imaging.Color,
                                  ByVal position As WatermarkPosition,
                                  Optional ByVal verticalmargin As Single = 0.0F,
                                  Optional ByVal horizontalmargin As Single = 0.0F) As Aspose.Imaging.Image
 
        Dim textformat As New Aspose.Imaging.StringFormat
        Dim textposition As Aspose.Imaging.PointF = Aspose.Imaging.PointF.Empty
        textformat.FormatFlags = Aspose.Imaging.StringFormatFlags.MeasureTrailingSpaces
 
        Select Case position
 
            Case WatermarkPosition.Top ' Note: horizontalmargin value is ignored.
                textposition = New Aspose.Imaging.PointF(x:=(img.Width \ 2), y:=verticalmargin)
                textformat.Alignment = Aspose.Imaging.StringAlignment.Center
 
            Case WatermarkPosition.TopLeft
                textposition = New Aspose.Imaging.PointF(x:=horizontalmargin, y:=verticalmargin)
                textformat.Alignment = Aspose.Imaging.StringAlignment.Near
 
            Case WatermarkPosition.TopRight
                Dim f As New System.Drawing.Font(fnt.Name, fnt.Size, DirectCast(fnt.Style, System.Drawing.FontStyle))
                Dim measure As System.Drawing.Size = TextRenderer.MeasureText(text, f)
                textposition = New Aspose.Imaging.PointF(x:=(img.Width - measure.Width - horizontalmargin), y:=verticalmargin)
                textformat.Alignment = Aspose.Imaging.StringAlignment.Near
 
            Case WatermarkPosition.Middle ' Note: verticalmargin horizontalmargin and values are ignored.
                textposition = New Aspose.Imaging.PointF(x:=(img.Width \ 2), y:=(img.Height \ 2))
                textformat.Alignment = Aspose.Imaging.StringAlignment.Center
 
            Case WatermarkPosition.MiddleLeft ' Note: verticalmargin value is ignored.
                textposition = New Aspose.Imaging.PointF(x:=(horizontalmargin), y:=(img.Height \ 2))
                textformat.Alignment = Aspose.Imaging.StringAlignment.Near
 
            Case WatermarkPosition.MiddleRight ' Note: verticalmargin value is ignored.
                Dim f As New System.Drawing.Font(fnt.Name, fnt.Size, DirectCast(fnt.Style, System.Drawing.FontStyle))
                Dim measure As System.Drawing.Size = TextRenderer.MeasureText(text, f)
                textposition = New Aspose.Imaging.PointF(x:=(img.Width - measure.Width - horizontalmargin), y:=(img.Height \ 2))
                textformat.Alignment = Aspose.Imaging.StringAlignment.Near
 
            Case WatermarkPosition.Bottom ' Note: horizontalmargin value is ignored.
                Dim f As New System.Drawing.Font(fnt.Name, fnt.Size, DirectCast(fnt.Style, System.Drawing.FontStyle))
                Dim measure As System.Drawing.Size = TextRenderer.MeasureText(text, f)
                textposition = New Aspose.Imaging.PointF(x:=(img.Width \ 2), y:=(img.Height - measure.Height - verticalmargin))
                textformat.Alignment = Aspose.Imaging.StringAlignment.Center
 
            Case WatermarkPosition.BottomLeft
                Dim f As New System.Drawing.Font(fnt.Name, fnt.Size, DirectCast(fnt.Style, System.Drawing.FontStyle))
                Dim measure As System.Drawing.Size = TextRenderer.MeasureText(text, f)
                textposition = New Aspose.Imaging.PointF(x:=(horizontalmargin), y:=(img.Height - measure.Height - verticalmargin))
                textformat.Alignment = Aspose.Imaging.StringAlignment.Near
 
            Case WatermarkPosition.BottomRight
                Dim f As New System.Drawing.Font(fnt.Name, fnt.Size, DirectCast(fnt.Style, System.Drawing.FontStyle))
                Dim measure As System.Drawing.Size = TextRenderer.MeasureText(text, f)
                textposition = New Aspose.Imaging.PointF(x:=(img.Width - measure.Width - horizontalmargin), y:=(img.Height - measure.Height - verticalmargin))
                textformat.Alignment = Aspose.Imaging.StringAlignment.Near
 
        End Select
 
        Using brush As New Aspose.Imaging.Brushes.SolidBrush With {.Color = color, .Opacity = 100.0F}
 
            ' Create and initialize an instance of Graphics class.
            Dim g As New Aspose.Imaging.Graphics(img)
 
            ' Draw a String using the SolidBrush object and Font, at specific Point and with specific format.
            g.DrawString(s:=text, font:=fnt, brush:=brush, point:=textposition, format:=textformat)
 
        End Using
 
        textformat.Dispose()
 
        ' Return the modified image.
        Return img
 
    End Function
 
    ''' <summary>
    ''' Specifies a Watermark position
    ''' </summary>
    Public Enum WatermarkPosition As Short
 
        ''' <summary>
        ''' Top position.
        ''' horizontalmargin value is ignored.
        ''' </summary>
        Top = 0S
 
        ''' <summary>
        ''' Top-Left position.
        ''' </summary>
        TopLeft = 1S
 
        ''' <summary>
        ''' Top-Right position.
        ''' </summary>
        TopRight = 2S
 
        ''' <summary>
        ''' Middle-Left position.
        ''' verticalmargin value is ignored.
        ''' </summary>
        MiddleLeft = 3S
 
        ''' <summary>
        ''' Middle position.
        ''' verticalmargin and horizontalmargin values are ignored.
        ''' </summary>
        Middle = 4S
 
        ''' <summary>
        ''' Middle-Right position.
        ''' verticalmargin value is ignored.
        ''' </summary>
        MiddleRight = 5S
 
        ''' <summary>
        ''' Bottom position.
        ''' horizontalmargin value is ignored.
        ''' </summary>
        Bottom = 6S
 
        ''' <summary>
        ''' Bottom-Left position.
        ''' </summary>
        BottomLeft = 7S
 
        ''' <summary>
        ''' Bottom-Right position.
        ''' </summary>
        BottomRight = 8S
 
    End Enum

Ejemplo de uso:

    Private Sub Form1_Load() Handles MyBase.Load
 
        ' Load an image to add a watermark.
        Dim img As Aspose.Imaging.Image = Aspose.Imaging.Image.Load("C:\sample.bmp")
 
        ' Set the watermark text.
        Dim text As String = "ElektroStudios"
 
        ' Set the watermark text color.
        Dim color As Aspose.Imaging.Color = Aspose.Imaging.Color.White
 
        ' Set the watermark text font.
        Dim fnt As New Aspose.Imaging.Font("Lucida Console", 32, FontStyle.Bold)
 
        ' Add the watermark into the image.
        img = Me.AddWatermark(img:=img, text:=text, fnt:=fnt, color:=color, position:=WatermarkPosition.BottomRight)
 
        ' Or...
        ' Dim position As New Aspose.Imaging.PointF(x:=10, y:=10)
        ' img = Me.AddWatermark(img:=img, text:=text, fnt:=fnt, color:=color, position:=position)
 
        ' Save the image to disk.
        img.Save("C:\Watermark.bmp")
 
        ' See the resulting image.
        Process.Start("C:\Watermark.bmp")
        Application.Exit()
 
    End Sub

WindowSticker
· Adhiere el Form a los bordes de la pantalla al mover la ventana cerca de los bordes.

Ejemplo de uso:

Private WindowSticker As New WindowSticker(ClientForm:=Me) With {.SnapMargin = 35}

' ***********************************************************************
' Author           : Elektro
' Last Modified On : 09-19-2014
' ***********************************************************************
' <copyright file="WindowSticker.vb" company="Elektro Studios">
'     Copyright (c) Elektro Studios. All rights reserved.
' </copyright>
' ***********************************************************************
 
#Region " Usage Examples "
 
' Private WindowSticker As New WindowSticker(ClientForm:=Me) With {.SnapMargin = 35}
 
'Private Sub Form1_Load() Handles MyBase.Shown
 
'    WindowSticker.Dispose()
'    WindowSticker = New WindowSticker(Form2)
'    WindowSticker.ClientForm.Show()
 
'End Sub
 
#End Region
 
#Region " Imports "
 
Imports System.ComponentModel
Imports System.Runtime.InteropServices
 
#End Region
 
#Region " WindowSticker "
 
''' <summary>
''' Sticks a Form to a Desktop border (if the Form is near).
''' </summary>
Public Class WindowSticker : Inherits NativeWindow : Implements IDisposable
 
#Region " Properties "
 
#Region " Public "
 
    ''' <summary>
    ''' Gets the client form used to stick its borders.
    ''' </summary>
    ''' <value>The client form used to stick its borders.</value>
    Public ReadOnly Property ClientForm As Form
        Get
            Return Me._ClientForm
        End Get
    End Property
    Private WithEvents _ClientForm As Form = Nothing
 
    ''' <summary>
    ''' Gets or sets the snap margin (offset), in pixels.
    ''' (Default value is: 30))
    ''' </summary>
    ''' <value>The snap margin (offset), in pixels.</value>
    Public Property SnapMargin As Integer
        Get
            Return Me._SnapMargin
        End Get
        Set(ByVal value As Integer)
            Me.DisposedCheck()
            Me._SnapMargin = value
        End Set
    End Property
    Private _SnapMargin As Integer = 30I
 
#End Region
 
#Region " Private "
 
    ''' <summary>
    ''' Gets rectangle that contains the size of the current screen.
    ''' </summary>
    ''' <value>The rectangle that contains the size of the current screen.</value>
    Private ReadOnly Property ScreenRect As Rectangle
        Get
            Return Screen.FromControl(Me._ClientForm).Bounds
        End Get
    End Property
 
    ''' <summary>
    ''' Gets the working area of the current screen.
    ''' </summary>
    ''' <value>The working area of the current screen.</value>
    Private ReadOnly Property WorkingArea As Rectangle
        Get
            Return Screen.FromControl(Me._ClientForm).WorkingArea
        End Get
    End Property
 
    ''' <summary>
    ''' Gets the desktop taskbar height (when thet taskbar is horizontal).
    ''' </summary>
    ''' <value>The desktop taskbar height (when thet taskbar is horizontal).</value>
    Private ReadOnly Property TaskbarHeight As Integer
        Get
            Return Me.ScreenRect.Height - Me.WorkingArea.Height
        End Get
    End Property
 
#End Region
 
#End Region
 
#Region " Enumerations "
 
    ''' <summary>
    ''' Windows Message Identifiers.
    ''' </summary>
    <Description("Messages to process in WndProc")>
    Public Enum WindowsMessages As Integer
 
        ''' <summary>
        ''' Sent to a window whose size, position, or place in the Z order is about to change.
        ''' MSDN Documentation: http://msdn.microsoft.com/en-us/library/windows/desktop/ms632653%28v=vs.85%29.aspx
        ''' </summary>
        WM_WINDOWPOSCHANGING = &H46I
 
    End Enum
 
#End Region
 
#Region " Structures "
 
    ''' <summary>
    ''' Contains information about the size and position of a window.
    ''' MSDN Documentation: http://msdn.microsoft.com/en-us/library/windows/desktop/ms632612%28v=vs.85%29.aspx
    ''' </summary>
    <StructLayout(LayoutKind.Sequential)>
    Public Structure WINDOWPOS
 
        ''' <summary>
        ''' A handle to the window.
        ''' </summary>
        Public hwnd As IntPtr
 
        ''' <summary>
        ''' The position of the window in Z order (front-to-back position). 
        ''' This member can be a handle to the window behind which this window is placed, 
        ''' or can be one of the special values listed with the 'SetWindowPos' function. 
        ''' </summary>
        Public hwndInsertAfter As IntPtr
 
        ''' <summary>
        ''' The position of the left edge of the window.
        ''' </summary>
        Public x As Integer
 
        ''' <summary>
        ''' The position of the top edge of the window.
        ''' </summary>
        Public y As Integer
 
        ''' <summary>
        ''' The window width, in pixels.
        ''' </summary>
        Public width As Integer
 
        ''' <summary>
        ''' The window height, in pixels.
        ''' </summary>
        Public height As Integer
 
        ''' <summary>
        ''' Flag containing the window position.
        ''' </summary>
        Public flags As Integer
 
    End Structure
 
#End Region
 
#Region " Constructor "
 
    ''' <summary>
    ''' Initializes a new instance of WindowSticker class.
    ''' </summary>
    ''' <param name="ClientForm">The client form to assign this NativeWindow.</param>
    Public Sub New(ByVal ClientForm As Form)
 
        ' Assign the Formulary.
        Me._ClientForm = ClientForm
 
    End Sub
 
    ''' <summary>
    ''' Prevents a default instance of the <see cref="WindowSticker"/> class from being created.
    ''' </summary>
    Private Sub New()
    End Sub
 
#End Region
 
#Region " Event Handlers "
 
    ''' <summary>
    ''' Assign the handle of the target Form to this NativeWindow,
    ''' necessary to override target Form's WndProc.
    ''' </summary>
    Private Sub SetFormHandle() Handles _ClientForm.HandleCreated, _ClientForm.Load, _ClientForm.Shown
 
        If (Me._ClientForm IsNot Nothing) AndAlso (Not MyBase.Handle.Equals(Me._ClientForm.Handle)) Then
 
            MyBase.AssignHandle(Me._ClientForm.Handle)
 
        End If
 
    End Sub
 
    ''' <summary>
    ''' Releases the Handle.
    ''' </summary>
    Private Sub OnHandleDestroyed() Handles _ClientForm.HandleDestroyed
 
        MyBase.ReleaseHandle()
 
    End Sub
 
#End Region
 
#Region " WndProc "
 
    ''' <summary>
    ''' Invokes the default window procedure associated with this window to process messages.
    ''' </summary>
    ''' <param name="m">
    ''' A <see cref="T:System.Windows.Forms.Message" /> that is associated with the current Windows message.
    ''' </param>
    Protected Overrides Sub WndProc(ByRef m As Message)
 
        If (Me._ClientForm IsNot Nothing) AndAlso (m.Msg = WindowsMessages.WM_WINDOWPOSCHANGING) Then
 
            Me.SnapToDesktopBorder(ClientForm:=Me._ClientForm, Handle:=m.LParam, widthAdjustment:=0)
 
        End If
 
        MyBase.WndProc(m)
 
    End Sub
 
#End Region
 
#Region " Private Methods "
 
    ''' <summary>
    ''' Sticks a Form to a desktop border (it its near).
    ''' </summary>
    ''' <param name="ClientForm">The client form used to stick its borders.</param>
    ''' <param name="Handle">A pointer to a 'WINDOWPOS' structure that contains information about the window's new size and position.</param>
    ''' <param name="widthAdjustment">The border width adjustment.</param>
    Private Sub SnapToDesktopBorder(ByVal ClientForm As Form,
                                    ByVal Handle As IntPtr,
                                    Optional ByVal widthAdjustment As Integer = 0I)
 
        Dim newPosition As WINDOWPOS = CType(Marshal.PtrToStructure(Handle, GetType(WINDOWPOS)), WINDOWPOS)
 
        If (newPosition.y = 0) OrElse (newPosition.x = 0) Then
            ' Nothing to do.
            Exit Sub
        End If
 
        ' Top border (check if taskbar is on top or bottom via WorkingRect.Y)
        If (newPosition.y >= -SnapMargin AndAlso (Me.WorkingArea.Y > 0 AndAlso newPosition.y <= (Me.TaskbarHeight + Me.SnapMargin))) _
        OrElse (Me.WorkingArea.Y <= 0 AndAlso newPosition.y <= (SnapMargin)) Then
 
            If Me.TaskbarHeight > 0 Then
                ' Horizontal Taskbar
                newPosition.y = Me.WorkingArea.Y
            Else
                ' Vertical Taskbar
                newPosition.y = 0
            End If
 
        End If
 
        ' Left border
        If (newPosition.x >= Me.WorkingArea.X - Me.SnapMargin) _
        AndAlso (newPosition.x <= Me.WorkingArea.X + Me.SnapMargin) Then
 
            newPosition.x = Me.WorkingArea.X
 
        End If
 
        ' Right border.
        If (newPosition.x + Me._ClientForm.Width <= Me.WorkingArea.Right + Me.SnapMargin) _
        AndAlso (newPosition.x + Me._ClientForm.Width >= Me.WorkingArea.Right - Me.SnapMargin) Then
 
            newPosition.x = (Me.WorkingArea.Right - Me._ClientForm.Width)
 
        End If
 
        ' Bottom border.
        If (newPosition.y + Me._ClientForm.Height <= Me.WorkingArea.Bottom + Me.SnapMargin) _
        AndAlso (newPosition.y + Me._ClientForm.Height >= Me.WorkingArea.Bottom - Me.SnapMargin) Then
 
            newPosition.y = (Me.WorkingArea.Bottom - Me._ClientForm.Height)
 
        End If
 
        ' Marshal it back.
        Marshal.StructureToPtr([structure]:=newPosition, ptr:=Handle, fDeleteOld:=True)
 
    End Sub
 
#End Region
 
#Region " Hidden Methods "
 
    ''' <summary>
    ''' Determines whether the specified System.Object instances are the same instance.
    ''' </summary>
    <EditorBrowsable(EditorBrowsableState.Never)>
    Private Shadows Sub ReferenceEquals()
    End Sub
 
    ''' <summary>
    ''' Assigns a handle to this window.
    ''' </summary>
    <EditorBrowsable(EditorBrowsableState.Never)>
    Public Shadows Sub AssignHandle()
    End Sub
 
    ''' <summary>
    ''' Creates a window and its handle with the specified creation parameters.
    ''' </summary>
    <EditorBrowsable(EditorBrowsableState.Never)>
    Public Shadows Sub CreateHandle()
    End Sub
 
    ''' <summary>
    ''' Destroys the window and its handle.
    ''' </summary>
    <EditorBrowsable(EditorBrowsableState.Never)>
    Public Shadows Sub DestroyHandle()
    End Sub
 
    ''' <summary>
    ''' Releases the handle associated with this window.
    ''' </summary>
    <EditorBrowsable(EditorBrowsableState.Never)>
    Public Shadows Sub ReleaseHandle()
    End Sub
 
    ''' <summary>
    ''' Retrieves the window associated with the specified handle.
    ''' </summary>
    <EditorBrowsable(EditorBrowsableState.Never)>
    Private Shadows Sub FromHandle()
    End Sub
 
    ''' <summary>
    ''' Serves as a hash function for a particular type.
    ''' </summary>
    <EditorBrowsable(EditorBrowsableState.Never)>
    Public Shadows Sub GetHashCode()
    End Sub
 
    ''' <summary>
    ''' Retrieves the current lifetime service object that controls the lifetime policy for this instance.
    ''' </summary>
    <EditorBrowsable(EditorBrowsableState.Never)>
    Public Shadows Function GetLifeTimeService()
        Return Nothing
    End Function
 
    ''' <summary>
    ''' Obtains a lifetime service object to control the lifetime policy for this instance.
    ''' </summary>
    <EditorBrowsable(EditorBrowsableState.Never)>
    Public Shadows Function InitializeLifeTimeService()
        Return Nothing
    End Function
 
    ''' <summary>
    ''' Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object.
    ''' </summary>
    <EditorBrowsable(EditorBrowsableState.Never)>
    Public Shadows Function CreateObjRef()
        Return Nothing
    End Function
 
    ''' <summary>
    ''' Determines whether the specified System.Object instances are considered equal.
    ''' </summary>
    <EditorBrowsable(EditorBrowsableState.Never)>
    Public Shadows Sub Equals()
    End Sub
 
    ''' <summary>
    ''' Returns a String that represents the current object.
    ''' </summary>
    <EditorBrowsable(EditorBrowsableState.Never)>
    Public Shadows Sub ToString()
    End Sub
 
    ''' <summary>
    ''' Invokes the default window procedure associated with this window.
    ''' </summary>
    <EditorBrowsable(EditorBrowsableState.Never)>
    Public Shadows Sub DefWndProc()
    End Sub
 
#End Region
 
#Region " IDisposable "
 
    ''' <summary>
    ''' To detect redundant calls when disposing.
    ''' </summary>
    Private IsDisposed As Boolean = False
 
    ''' <summary>
    ''' Prevent calls to methods after disposing.
    ''' </summary>
    ''' <exception cref="System.ObjectDisposedException"></exception>
    Private Sub DisposedCheck()
 
        If Me.IsDisposed Then
            Throw New ObjectDisposedException(Me.GetType().FullName)
        End If
 
    End Sub
 
    ''' <summary>
    ''' Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
    ''' </summary>
    Public Sub Dispose() Implements IDisposable.Dispose
        Dispose(True)
        GC.SuppressFinalize(Me)
    End Sub
 
    ''' <summary>
    ''' Releases unmanaged and - optionally - managed resources.
    ''' </summary>
    ''' <param name="IsDisposing">
    ''' <c>true</c> to release both managed and unmanaged resources; 
    ''' <c>false</c> to release only unmanaged resources.
    ''' </param>
    Protected Sub Dispose(ByVal IsDisposing As Boolean)
 
        If Not Me.IsDisposed Then
 
            If IsDisposing Then
                Me._ClientForm = Nothing
                MyBase.ReleaseHandle()
                MyBase.DestroyHandle()
            End If
 
        End If
 
        Me.IsDisposed = True
 
    End Sub
 
#End Region
 
End Class
 
#End Region

He tomado una antigua class del cajón de los recuerdos (o experimentos xD) que servía como medidor de tiempo para un cronómetro o una cuenta atrás y lo he mejorado y simplificado bastante.

Ejemplo de uso:

Public Class form1
 
    ''' <summary>
    ''' The <see cref="TimeMeasurer"/> instance that measure time intervals.
    ''' </summary>
    Private WithEvents Clock As New TimeMeasurer With {.UpdateInterval = 100}
 
    Private ctrl_ElapsedTime As Control ' Control used to display the time elapsed interval.
    Private ctrl_RemainingTime As Control ' Control used to display the time remaining interval.
 
    Private Shadows Sub Load() Handles MyBase.Load
 
        ctrl_ElapsedTime = Label1
        ctrl_RemainingTime = Label2
 
        Me.Clock.Start(60000) ' Measure 1 minute
 
        ' Or...
        ' Me.Clock.Stop() ' Stop temporally the time interval measurement.
        ' Me.Clock.Resume() ' Resume a previouslly stopped time interval measurement.
        ' Dim ClockState As TimeMeasurer.TimeMeasurerState = Me.Clock.State ' Get the state.
 
    End Sub
 
    Private Sub Clock_ElapsedTimeUpdated(ByVal sender As Object, ByVal e As TimeMeasurer.TimeMeasureEventArgs) _
    Handles Clock.ElapsedTimeUpdated
 
        ' Measure H:M:S:MS
        ctrl_ElapsedTime.Text = String.Format("{0:00}:{1:00}:{2:00}:{3:000}",
                                              e.Hour, e.Minute, e.Second, e.Millisecond)
 
    End Sub
 
    Private Sub Clock_RemainingTimeUpdated(ByVal sender As Object, ByVal e As TimeMeasurer.TimeMeasureEventArgs) _
    Handles Clock.RemainingTimeUpdated
 
        ' Measure H:M:S:MS
        ctrl_RemainingTime.Text = String.Format("{0:00}:{1:00}:{2:00}:{3:000}",
                                                e.Hour, e.Minute, e.Second, e.Millisecond)
 
        '' Measure H:M:S
        'ctrl_RemainingTime.Text = String.Format("{0:00}:{1:00}:{2:00}",
        '                                        e.Hour, e.Minute, e.Second + 1)
 
    End Sub
 
    Private Sub Clock_ElapsedTimeFinished(ByVal sender As Object, ByVal e As TimeMeasurer.TimeMeasureEventArgs) _
    Handles Clock.ElapsedTimeFinished
 
        ' Measure H:M:S:MS
        ctrl_ElapsedTime.Text = String.Format("{0:00}:{1:00}:{2:00}:{3:000}",
                                              e.Hour, e.Minute, e.Second, e.Millisecond)
 
    End Sub
 
    Private Sub Clock_RemainingTimeFinished(ByVal sender As Object, ByVal e As TimeMeasurer.TimeMeasureEventArgs) _
    Handles Clock.RemainingTimeFinished
 
        ' Measure H:M:S:MS
        ctrl_RemainingTime.Text = String.Format("{0:00}:{1:00}:{2:00}:{3:000}",
                                                e.Hour, e.Minute, e.Second, e.Millisecond)
 
    End Sub
 
End Class

Como veis es muy sencillo de usar y de una manera más genérica (mucho más que el antiguo código que ecribí)

El source:

' ***********************************************************************
' Author           : Elektro
' Last Modified On : 10-02-2014
' ***********************************************************************
' <copyright file="TimeMeasurer.vb" company="Elektro Studios">
'     Copyright (c) Elektro Studios. All rights reserved.
' </copyright>
' ***********************************************************************
 
#Region " Usage Examples "
 
'Public Class TimeMeasurer_Test
'
'    ''' <summary>
'    ''' The <see cref="TimeMeasurer"/> instance that measure time intervals.
'    ''' </summary>
'    Private WithEvents Clock As New TimeMeasurer With {.UpdateInterval = 100}
'
'    Private ctrl_ElapsedTime As Control ' Control used to display the time elapsed interval.
'    Private ctrl_RemainingTime As Control ' Control used to display the time remaining interval.
'
'    Private Shadows Sub Load() Handles MyBase.Load
'
'        ctrl_ElapsedTime = LabelElapsed
'        ctrl_RemainingTime = LabelRemaining
'
'        Me.Clock.Start(60000) ' Measure 1 minute
'
'        ' Or...
'        ' Me.Clock.Stop() ' Stop temporally the time interval measurement.
'        ' Me.Clock.Resume() ' Resume a previouslly stopped time interval measurement.
'        ' Dim ClockState As TimeMeasurer.TimeMeasurerState = Me.Clock.State ' Get the state.
'
'    End Sub
'
'    ''' <summary>
'    ''' Handles the ElapsedTimeUpdated event of the Clock instance.
'    ''' </summary>
'    ''' <param name="sender">The source of the event.</param>
'    ''' <param name="e">The <see cref="TimeMeasurer.TimeMeasureEventArgs"/> instance containing the event data.</param>
'    Private Sub Clock_ElapsedTimeUpdated(ByVal sender As Object, ByVal e As TimeMeasurer.TimeMeasureEventArgs) _
'    Handles Clock.ElapsedTimeUpdated
'
'        ' Measure H:M:S:MS
'        ctrl_ElapsedTime.Text = String.Format("{0:00}:{1:00}:{2:00}:{3:000}",
'                                              e.Hour, e.Minute, e.Second, e.Millisecond)
'
'        ' Measure H:M:S
'        ctrl_ElapsedTime.Text = String.Format("{0:00}:{1:00}:{2:00}",
'                                              e.Hour, e.Minute, e.Second)
'
'    End Sub
'
'    ''' <summary>
'    ''' Handles the RemainingTimeUpdated event of the Clock instance.
'    ''' </summary>
'    ''' <param name="sender">The source of the event.</param>
'    ''' <param name="e">The <see cref="TimeMeasurer.TimeMeasureEventArgs"/> instance containing the event data.</param>
'    Private Sub Clock_RemainingTimeUpdated(ByVal sender As Object, ByVal e As TimeMeasurer.TimeMeasureEventArgs) _
'    Handles Clock.RemainingTimeUpdated
'
'        ' Measure H:M:S:MS
'        ctrl_RemainingTime.Text = String.Format("{0:00}:{1:00}:{2:00}:{3:000}",
'                                                e.Hour, e.Minute, e.Second, e.Millisecond)
'
'        ' Measure H:M:S
'        ctrl_RemainingTime.Text = String.Format("{0:00}:{1:00}:{2:00}",
'                                                e.Hour, e.Minute, e.Second + 1)
'
'    End Sub
'
'    ''' <summary>
'    ''' Handles the ElapsedTimeFinished event of the Clock instance.
'    ''' </summary>
'    ''' <param name="sender">The source of the event.</param>
'    ''' <param name="e">The <see cref="TimeMeasurer.TimeMeasureEventArgs"/> instance containing the event data.</param>
'    Private Sub Clock_ElapsedTimeFinished(ByVal sender As Object, ByVal e As TimeMeasurer.TimeMeasureEventArgs) _
'    Handles Clock.ElapsedTimeFinished
'
'        ' Measure H:M:S:MS
'        ctrl_ElapsedTime.Text = String.Format("{0:00}:{1:00}:{2:00}:{3:000}",
'                                              e.Hour, e.Minute, e.Second, e.Millisecond)
'
'        ' Measure H:M:S
'        ctrl_ElapsedTime.Text = String.Format("{0:00}:{1:00}:{2:00}",
'                                              e.Hour, e.Minute, e.Second)
'
'    End Sub
'
'    ''' <summary>
'    ''' Handles the RemainingTimeFinished event of the Clock instance.
'    ''' </summary>
'    ''' <param name="sender">The source of the event.</param>
'    ''' <param name="e">The <see cref="TimeMeasurer.TimeMeasureEventArgs"/> instance containing the event data.</param>
'    Private Sub Clock_RemainingTimeFinished(ByVal sender As Object, ByVal e As TimeMeasurer.TimeMeasureEventArgs) _
'    Handles Clock.RemainingTimeFinished
'
'        ' Measure H:M:S:MS
'        ctrl_RemainingTime.Text = String.Format("{0:00}:{1:00}:{2:00}:{3:000}",
'                                                e.Hour, e.Minute, e.Second, e.Millisecond)
'
'        ' Measure H:M:S
'        ctrl_RemainingTime.Text = String.Format("{0:00}:{1:00}:{2:00}",
'                                                e.Hour, e.Minute, e.Second)
'
'    End Sub
'
'End Class
 
#End Region
 
#Region " Option Statements "
 
Option Strict On
Option Explicit On
Option Infer Off
 
#End Region
 
#Region " Imports "
 
Imports System.ComponentModel
 
#End Region
 
''' <summary>
''' Measure a time interval.
''' This can be used as a chronometer or countdown timer.
''' </summary>
Public NotInheritable Class TimeMeasurer
 
#Region " Objects "
 
    ''' <summary>
    ''' <see cref="Stopwatch"/> instance to retrieve the elapsed time.
    ''' </summary>
    Private TimeElapsed As Stopwatch
 
    ''' <summary>
    ''' <see cref="TimeSpan"/> instance to retrieve the remaining time.
    ''' </summary>
    Private TimeRemaining As TimeSpan
 
    ''' <summary>
    ''' <see cref="Timer"/> instance that updates the elapsed and remaining times and raises the events.
    ''' </summary>
    Private WithEvents MeasureTimer As Timer
 
    ''' <summary>
    ''' Indicates wheter the <see cref="TimeMeasurer"/> instance has finished to measure intervals.
    ''' </summary>
    Private IsFinished As Boolean
 
#End Region
 
#Region " Properties "
 
    ''' <summary>
    ''' Gets the current state of this <see cref="TimeMeasurer"/> instance.
    ''' </summary>
    ''' <value>The update interval.</value>
    Public ReadOnly Property State As TimeMeasurerState
        Get
            If Me.IsFinished Then
                Return TimeMeasurerState.Finished
 
            ElseIf (Me.TimeElapsed Is Nothing) OrElse Not (Me.TimeElapsed.IsRunning) Then
                Return TimeMeasurerState.Stopped
 
            Else
                Return TimeMeasurerState.Running
 
            End If
        End Get
    End Property
 
    ''' <summary>
    ''' Gets or sets the update interval.
    ''' </summary>
    ''' <value>The update interval.</value>
    Public Property UpdateInterval As Integer
        Get
            Return Me._UpdateInterval
        End Get
        Set(ByVal value As Integer)
            Me._UpdateInterval = value
            If Me.MeasureTimer IsNot Nothing Then
                Me.MeasureTimer.Interval = value
            End If
        End Set
    End Property
    ''' <summary>
    ''' The update interval
    ''' </summary>
    Private _UpdateInterval As Integer = 100I
 
#End Region
 
#Region " Enumerations "
 
    ''' <summary>
    ''' Specifies the current state of a <see cref="TimeMeasurer"/> instance.
    ''' </summary>
    <Description("Enum used as return value of 'State' property.")>
    Public Enum TimeMeasurerState As Integer
 
        ''' <summary>
        ''' The <see cref="TimeMeasurer"/> instance is running and measuring time intervals.
        ''' </summary>
        Running = 0I
 
        ''' <summary>
        ''' The <see cref="TimeMeasurer"/> instance is temporally stopped, waiting to resume.
        ''' </summary>
        Stopped = 1I
 
        ''' <summary>
        ''' The <see cref="TimeMeasurer"/> instance has finished to measure the time intervals.
        ''' </summary>
        Finished = 2I
 
    End Enum
 
#End Region
 
#Region " Events "
 
    ''' <summary>
    ''' Occurs when the elapsed time updates.
    ''' </summary>
    Public Event ElapsedTimeUpdated(ByVal sender As Object, ByVal e As TimeMeasureEventArgs)
 
    ''' <summary>
    ''' Occurs when the remaining time updates.
    ''' </summary>
    Public Event RemainingTimeUpdated(ByVal sender As Object, ByVal e As TimeMeasureEventArgs)
 
    ''' <summary>
    ''' Occurs when the elapsed time finishes.
    ''' </summary>
    Public Event ElapsedTimeFinished(ByVal sender As Object, ByVal e As TimeMeasureEventArgs)
 
    ''' <summary>
    ''' Occurs when the elapsed time finishes.
    ''' </summary>
    Public Event RemainingTimeFinished(ByVal sender As Object, ByVal e As TimeMeasureEventArgs)
 
    ''' <summary>
    ''' Contains the <see cref="TimeMeasureEventArgs"/> arguments.
    ''' </summary>
    Public Class TimeMeasureEventArgs : Inherits EventArgs
 
        ''' <summary>
        ''' Gets or sets the hour.
        ''' </summary>
        ''' <value>The hour.</value>
        Public Property Hour As Double
 
        ''' <summary>
        ''' Gets or sets the minute.
        ''' </summary>
        ''' <value>The minute.</value>
        Public Property Minute As Double
 
        ''' <summary>
        ''' Gets or sets the Second.
        ''' </summary>
        ''' <value>The Second.</value>
        Public Property Second As Double
 
        ''' <summary>
        ''' Gets or sets the Millisecond.
        ''' </summary>
        ''' <value>The Millisecond.</value>
        Public Property Millisecond As Double
 
    End Class
 
#End Region
 
#Region " Public Methods "
 
    ''' <summary>
    ''' Starts the time interval measurement from zero.
    ''' </summary>
    ''' <param name="Milliseconds">Indicates the time interval to measure, in milliseconds.</param>
    Public Sub Start(ByVal Milliseconds As Double)
 
        If Milliseconds > (TimeSpan.MaxValue.TotalMilliseconds - 1001.0R) Then
            Throw New ArgumentOutOfRangeException("Milliseconds",
                                                  String.Format("The value can't be greater than {0}",
                                                                CStr(TimeSpan.MaxValue.TotalMilliseconds - 1001.0R)))
        End If
 
        Me.TimeElapsed = New Stopwatch
        Me.TimeRemaining = TimeSpan.FromMilliseconds(Milliseconds)
        Me.MeasureTimer = New Timer With
           {
             .Tag = Milliseconds,
             .Interval = Me.UpdateInterval,
             .Enabled = True
           }
 
        Me.TimeElapsed.Start()
        Me.MeasureTimer.Start()
 
    End Sub
 
    ''' <summary>
    ''' Stops the time interval measurement.
    ''' </summary>
    Public Sub [Stop]()
 
        If (Me.MeasureTimer Is Nothing) OrElse Not (Me.TimeElapsed.IsRunning) Then
            Throw New Exception("TimeMeasurer is not running.")
 
        Else
            Me.MeasureTimer.Stop()
            Me.TimeElapsed.Stop()
 
        End If
 
    End Sub
 
    ''' <summary>
    ''' Resumes the time interval measurement.
    ''' </summary>
    Public Sub [Resume]()
 
        If (Me.MeasureTimer Is Nothing) OrElse (Me.TimeElapsed.IsRunning) Then
            Throw New Exception("TimeMeasurer is not stopped.")
 
        Else
            Me.MeasureTimer.Start()
            Me.TimeElapsed.Start()
 
        End If
 
    End Sub
 
#End Region
 
#Region " Private Methods "
 
    ''' <summary>
    ''' Stops Time intervals and resets the elapsed and remaining time to zero.
    ''' </summary>
    Private Sub Reset()
 
        Me.MeasureTimer.Stop()
        Me.TimeElapsed.Reset()
 
    End Sub
 
#End Region
 
#Region " Event Handlers "
 
    ''' <summary>
    ''' Handles the Tick event of the MeasureTimer control.
    ''' </summary>
    ''' <param name="sender">The source of the event.</param>
    ''' <param name="e">The <see cref="EventArgs"/> instance containing the event data.</param>
    Private Sub MeasureTimer_Tick(ByVal sender As Object, ByVal e As EventArgs) _
    Handles MeasureTimer.Tick
 
        Dim TimeDifference As TimeSpan = (Me.TimeRemaining - Me.TimeElapsed.Elapsed)
        Dim ElapsedArgs As New TimeMeasureEventArgs
        Dim RemainingArgs As New TimeMeasureEventArgs
 
        If (TimeDifference.TotalMilliseconds <= 0.0R) _
        OrElse (Me.TimeElapsed.ElapsedMilliseconds > DirectCast(Me.MeasureTimer.Tag, Double)) Then
 
            Dim TotalTime As TimeSpan = TimeSpan.FromMilliseconds(DirectCast(Me.MeasureTimer.Tag, Double))
 
            With ElapsedArgs
                .Hour = TotalTime.Hours
                .Minute = TotalTime.Minutes
                .Second = TotalTime.Seconds
                .Millisecond = TotalTime.Milliseconds
            End With
 
            With RemainingArgs
                .Hour = 0.0R
                .Minute = 0.0R
                .Second = 0.0R
                .Millisecond = 0.0R
            End With
 
            Me.Reset()
            Me.IsFinished = True
            RaiseEvent ElapsedTimeFinished(Me.TimeElapsed, ElapsedArgs)
            RaiseEvent RemainingTimeFinished(TimeDifference, RemainingArgs)
 
        Else
 
            With ElapsedArgs
                .Hour = TimeElapsed.Elapsed.Hours
                .Minute = TimeElapsed.Elapsed.Minutes
                .Second = TimeElapsed.Elapsed.Seconds
                .Millisecond = TimeElapsed.Elapsed.Milliseconds
            End With
 
            With RemainingArgs
                .Hour = Math.Floor(TimeDifference.TotalHours) Mod TimeSpan.MaxValue.TotalMilliseconds
                .Minute = Math.Floor(TimeDifference.TotalMinutes) Mod 60.0R
                .Second = Math.Floor(TimeDifference.TotalSeconds) Mod 60.0R
                .Millisecond = Math.Floor(TimeDifference.TotalMilliseconds Mod 1000.0R)
            End With
 
            RaiseEvent ElapsedTimeUpdated(Me.TimeElapsed, ElapsedArgs)
            RaiseEvent RemainingTimeUpdated(TimeDifference, RemainingArgs)
 
        End If
 
    End Sub
 
#End Region
 
End Class