In Windows, some audio applications will take exclusive control of an audio device's driver while in use so that other applications can not play audio through that device at the same time. Depending on the audio applications you use, this can cause audio not to be played through your Apollo interface from one application while another application is open. Disabling the Exclusive Mode options in Windows Sound Preferences can resolve this by preventing audio applications from taking exclusive control of the Apollo's driver. 

To disable Exclusive Mode for the Apollo, follow the directions below:

1. Open Control Panel > Hardware and Sound > Sound and click on the Playback tab

2. Select the Apollo from the list of audio devices and then click Properties

3. In the Properties window, go to the Advanced tab and un-check the option to "Allow applications to take exclusive control of this device"

4. Click OK to Apply the settings

5. Back in the Sound window, click on the Recording tab and repeat steps 2-4

Once complete, restart your computer for the changes to take effect.