It looks like your PC's sound device is missing. You didn't post your system specs so we can only guess or offer general suggestions on trying to fix it.
Your "Speakers" should be shown and set as the default Playback device. In the Recording section you should have "Stereo Mix" or "System Mixer" listed and that should be your default recording device and then any audio input - Mic, Line in or streaming audio from the Internet can be used and recorded.
What is the status of your PC sound device in the Device Manager? Is is listed? If its listed, does it show an error code or "working OK"? Also if its listed, does it show the correct sound device (e.g. RealTek) or does it show the generic Windows installed HD Audio Codec? If it has the HD Audio Codec the sound driver
from your PC vendor needs to be installed. If it shows as working OK, RIGHT click on the entry for the sound and then LEFT click "uninstall". DO NO check the box to uninstall the drivers
and then restart the PC and when Windows starts it will detect and reinstall it. This fixes many Windows status corruption issues.
Many possibilities and more information is really needed.