Right click the speaker in system tray located in the bottom right corner of the screen. Select playback devices for speakers and recording devices for microphone.
-  Click "Speakers" and click "Properties" at the right bottom of this window. 
 

- In “Speakers Properties” dialogue box, click “Levels” tab, drag the slider under “Realtek HD Audio output” to adjust output sound volume and then click “OK”. 
 

- Note: If the speaker icon is displayed as 
 ,  it means that the speaker is muted. You can click this icon to cancel “Mute”. 
 
- To adjust microphone volume, click “Recording” tab in “Sound” dialogue box. Click “Microphone” (it is required to select microphone already connected to PC (microphone with green checkmark)), and click “Properties”
 

- In “Microphone Properties” dialogue box, click “Levels” tab. Drag the slider under “Microphone”  to adjust speaker volume, and then click “OK”. 
 
