When we try to play DVD's, we get a error message saying "cannot play DVD because a compatible DVD decoder is not installed on your computer". And we used to be able to play DVD's. A few months ago we had Geek Squad get rid of a bunch of viruses. Im wondering if they erased or if the viruses did??? Is there a way to reinstall one without having to buy one? And if not, where is a good place to purchase? :(