I have three DVD's that have been copied that lock up my system when I try to play them. The movies all work on my set top player without any problems. The movies were not created on my computer they were done on a friends system. I wanted to copy the movies and none of them work in Nero, DVD shrink or decypter. There is no protection on them. Could it be the type of media that was used, and is it possible my DVD drive is not compatible?