You recorded your screen, but the sound track cannot be recorded?
The following steps will solve the problem:

1. Open the Control Panel and click on "Hardware and Sound", then on "Sound".
   
2. Right click on any device and select "Show Disabled and unconnected devices". 
3. Right-click on the "Stereomix" entry and activate the device.
4. Mark "Stereomix" as your default recording device.
5. Open the screen capture tool via the menu "Project > Screen Capture".
6. Select the desired display and the source "Stereomix" by clicking once onto their frames
7. Perform screen recording again.