So many of us lost all audio output after the anniversary update, even after a system reset or a clean windows install, thanks to user "BECAUSEICAN" and "HGMARTIN9" who posted their solution for the SW5-012 and also worked for my SW3-013.
1) Go to: http://www.acer.com/ac/en/US/content/drivers
2) Bring up the SW5-012
3) In driver, download the following:
- Realtek Audio Driver
- Platform Drivers
4) Go back to SW3-013
5) In Application, download 'Quick Access'
6) Go to Device Manager>View>Show hidden devices. If you have other devices> IWD Aud-Device_6, uninstall it. Then, restart your system. Install Reltek and then restart system. Install Quick Access and then restart. Finally install Platform Drivers. Restart and you should have sound.
I hope this will help many people, it was beginning to frustrate me.