Non è necessario copiare l'intera Form per avere uno screenShot, basta anche solo un controllo.

codice:
 Public Sub CreateScreenShot(ByVal controllo As Control)
        Dim frmGraphics As Graphics = controllo.CreateGraphics()
        Dim rect As Rectangle = controllo.ClientRectangle
        Dim bmp As New Bitmap(rect.Width, rect.Height, frmGraphics)
        frmGraphics.Dispose()
        Dim picGraphics As Graphics = Graphics.FromImage(bmp)
        picGraphics.CopyFromScreen(controllo.PointToScreen(New Point(rect.Left, rect.Top)), New Point(0, 0), New Size(rect.Width, rect.Height))
        bmp.Save("C:\screeShot.jpg", System.Drawing.Imaging.ImageFormat.Jpeg)
        picGraphics.Dispose()
    End Sub
Ovviamente il controllo deve essere visibile.

Il resto a te.