Right-click specifically over the input device you want to record with (in this case 'Stereo Mix' or whatever alternative you have), and if visible, choose 'Enable'.

Right-click anywhere inside the empty, white, space and choose 'Show disabled devices' then right-click again and choose 'Show Disconnected Devices'.

Right-click over the Speaker icon by the system clock then choose Sounds the click on the Recording tab.

To show or enable inputs, launch the sound device control panel from the Windows Control Panel or from the system tray (by the clock). Earlier Windows systems may also need the input for recording computer playback to be made visible before Audacity can use it. Windows, computers almost always only have microphone inputs enabled by default. Plug in any 1/8 inch (3.5 mm) minijack plug with no lead attached.Plug in external speakers or headphones and turn those down.Click the speaker by the system clock, click the 'Mixer' link, then mute the 'Device' slider at far left of the 'Volume Mixer' window.If this happens then to make a recording without hearing it, you can try the following: However on some devices, turning down either slider may turn down or silence the achieved recording level. This means that if you do not want to hear what you are recording, you can simply turn down either Audacity volume slider. When the Audacity recording and playback sliders are linked, adjusting either slider will often not affect the level already being recorded.This will often happen if in Audacity you set the (loopback) recording device to the same built-in device as the one selected for playback.

On many devices, the Audacity recording volume and playback volume sliders will be 'linked' so that both sliders move when you move either slider, and either slider will affect the level of the audio that you hear.The behavior of the Audacity playback and recording sliders may vary according to the sound device you are recording from. Playback and Recording sliders when using WASAPI

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