Symptoms
When you open the Audio Device setup by selecting Tools > Options > Audio Device in Microsoft Lync 2013 (Microsoft Skype for Business) that has December 8, 2015 security update installed, you can't see the PC Mic and Speakers device in the Audio Device drop-down menu. Instead, you may see two duplicate device names.
Resolution
To fix this issue, install the June 7, 2016, update (KB3115033) for Lync 2013 (Skype for Business).Note Lync 2013 was upgraded to Skype for Business in April 2015.
