Third party programs can prevent Blizzard games from accessing your microphone, speakers, or headset. Disabling exclusive control of your hardware may fix sound or voice-chat related issues. To disable exclusive control, follow the steps below.

1. Press Windows+R
2. Type mmsys.cpl into the run prompt, then press Enter
3. Right click your speakers or headset and select Properties
4. Click the Advanced tab
5. Uncheck the box for Allow applications to take exclusive control of this device
6. Click Apply, then OK
7. Click the Recording tab
8. Repeat steps 3-6 for your microphone or headset