I installed QuickTime 7 (7.6.6) yesterday as I needed to play an AVI file, which requires certain codec and couldn't run with Perian. The file was played quite well yesterday, but now I don't have sound at all. Just MUTE.
I don't see "built in speakers" in Application\Utilities\Audio and MIDI Configuration. somehow my audio card is just missing. I'm running Macbook Air 10.7.5
The folder System\Library\QuickTime contains the following:
Is it better to restore my sistem? (which is quite a fuss because there's no internal DVD rom) or is there any way to solve this?