Public Class CentralException
    Implements IDisposable
    Dim logFile As String = "log.txt"
    Dim sw As IO.StreamWriter
    Sub New()
        sw = New IO.StreamWriter(logFile, True)
        sw.WriteLine("")
        sw.WriteLine(New String("#", 20))
        sw.WriteLine("Start:" + DateTime.Now.ToString, 20)
    End Sub
    Public Sub CentralExceptionHandler(ByVal sender As Object, ByVal e As _
      Threading.ThreadExceptionEventArgs)
        sw.WriteLine(New String("-", 20))
        sw.WriteLine("Zeitpunkt: " + DateTime.Today.ToString)
        sw.WriteLine(e.Exception.Message)
        sw.WriteLine(New String("-", 20))
        MessageBox.Show(e.Exception.Message)
    End Sub
    Protected Overrides Sub Finalize()
        sw.WriteLine("End:" + DateTime.Now.ToString, 20)
        sw.WriteLine(New String("#", 20))
        sw.WriteLine("")
        sw.Close()
        MyBase.Finalize()
    End Sub
    Public Sub Dispose() Implements System.IDisposable.Dispose
        GC.SuppressFinalize(Me)
        Me.Finalize()
    End Sub
End Class

Class StartClass
    Public Shared Sub Main()
        Dim frmStart As New Form1
        Dim centEx As New CentralException
        AddHandler Application.ThreadException, AddressOf _
          centEx.CentralExceptionHandler
        Application.Run(frmStart)
        centEx.Dispose()
    End Sub
End Class