Cannot Use AirPlay On Mac OS X 10.7.5
Hello, my family and I have bought an Apple TV today and we figured out how to use AirPlay on our iPhones, and we have three computers in use. Only one of them is able to use the AirPlay Mirroring feature. The two that can't are OS X 10.7.5. If I am correct, I need version 10.8 of OS X Mountain Lion. My issue is that the two computers are saying everything is up to date. Would I need to go an Apple store to physically update the computers? Any help would be appreciated!
Apple TV, Mac OS X (10.7.5)