windows was upgraded from 8.0 to 8.1 and the audio was affected. The sound is muffled and upgraded some drivers, but it affected the visual when playing a DVD. Need a driver for dolby 5.1 but dolby doesn't provide drivers. Thought that windows would have fixed it in one of their upgrades, but no! Looking for a reliable driver that won't mess with the picture. Have lenovo n585 laptop. thanks