Configuring Windows For Recording
If Windows is not correctly setup to record audio from applications, your recording may be -
Blank
Distorted
Too quiet
Have unwanted background noises picked up from the room
On most systems you should be able to enable the required recording device as follows:
Open Control Panel In Classic view, Double click Sound. Click the Recording tab. ( If you clicked 'Mix' on the recording interface, this panel should have already opened for you ). You should see a panel similar to the one below.
If you only see "microphone" and/or "line-in", right-click anywhere in the blank white area of the window to display the Show Disabled Devices context menu.
Select Show Disabled Devices:
If Stereo Mix, Wave-Out Mix, Mixer, Wave, What U Hear ( or something similar ) is visible then right click on that entry and choose enable:
To make this newly enabled device the default recording device, highlight it and click the Set Default button, or right-click on the device and select Set as Default Device. ( Shown below )

Next, right click the Line In / Mic channel ( This may be marked only as Microphone ) and select disable.
You should now be ready to record.
If you still find your recordings are too quiet or distorted, you can highlight the 'What U Hear' channel, click 'Properties', then the 'Levels' tab and adjust the slider until you find a suitable recording level. You can then make adjustments using the Sensitivity slider on the recording interface within the application.