Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        Dim ruta As String
        ruta = Directory.GetCurrentDirectory & "\dep.exe"
        Process.Start(ruta)
    End Sub

Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)

 If UnloadMode = 0 Then 'Significa que se ha cerrado con la X:
    MsgBox "Has pulsado la X del formulario"
    Call borrar_archivos_temporales
End If

End Sub

Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)

 If UnloadMode = 0 Then 'Significa que se ha cerrado con la X:
    MsgBox "Has pulsado la X del formulario"
    Cancel = 1
End If

End Sub