I am not able to hear any sound from my acer desktop computer running windows 8.1. I have tried to reinstall the high definition audio drivers which I downloaded from Realtek but am having no success. When i look in my device manager under sounds I see nothing. I am getting the message that "no audio devices are installed". If someone can help me with this problem I would be grateful. I tried the refresh option but am getting error messages there too and there are no restore points in memory. I am at a loss.