I had this problem for months, and I finally found some advice online that solved my problem. Plug in the easycap adapter and try this :

Control Panel > Device Manager > Sound, Video, Game controllers > Right click on the USB audio device > Select "update drivers" > Wait a few minutes.

After this, Windows may update your drivers with "EMP AUDIO DEVICE". If/when it does this, try again and see what happens. I hope that helps !