I need more information. What gpu are you using, what video output are you using. I recommend just using hdmi as it outputs video and audio. But if you are trying to use headphones only, plug them into the front of the pc (or back) and right click the speaker/volume icon on the tray area of windows. Then select playback devices and tell me what pops up
You must think I'm stupid.
XFX Radeon R7 250x Core Edition 2 GB edition.
I am using HDMI, who doesn't?
I plugged them into all the jacks, and selected playback, who wouldn't do that?
(sorry if I seemed angry, I get grumpy without my vape pen and it's charging)