Option Explicit

Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Long
Private Declare Function SetForegroundWindow Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function ShowWindow Lib "user32" (ByVal hwnd As Long, ByVal nCmdShow As Long) As Long

Private Sub Form_Load()

Dim CaptionVerdadero As String: CaptionVerdadero = Me.Caption

If App.PrevInstance Then
  Me.Caption = "INSTANCIA 2"
  Call ShowWindow(FindWindow(vbNullString, CaptionVerdadero), 1)
  Call SetForegroundWindow(FindWindow(vbNullString, CaptionVerdadero))
  End
End If

End Sub