I have a MacBook Pro 2.66 Intel Core 2 Duo. Recently I upgraded my OS to Lion and I have started experiencing issues. For one in System Preferences my Sound Card no longer has System Sound, instead it has something called Nielsen Audio. The only other options are my Bluetooth Nokia Headset and Headphones. I cannot get the volume to increase like I could before I loaded Lion. Also My AirPort has now changed to WiFi and it is not responding when i use the new Internet Sharing option. Can someone help me reload the correct Sound Card driver and fix these other issues?