No sound in speakers/headphones when HDMI connected

Apparently it's not possible to output sound through both the HDMI and the headphone jack simultaneously.  But If you want to watch video through HDMI and listen via headphone jack do this:

Right click on the speaker icon in the taskbar > left click playback devices > right click HDMI > disable

OPTION 2

change the default playback device for the internal soundcard instead of the HDMI

https://answers.microsoft.com/en-us/windows/forum/windows_8-pictures/how-to-use-hdmi-and-headphone-jack-simultaneously/5b0ad7ba-6c86-49de-a23d-233d6fcc099e