No sound from desktop at all?

Ive been trying for the past few days to get sound playing on my desktop, I've tried using speakers, no sound,, tried switching hdmi cords, and it isnt a tv problem because i can hear my games from xbox, and tried uninstalling and reinstalling niveda drivers, and now the sound icon appears with an x, when I try to fix it, it just says "insert audio cord into jack" and I've presetted it so it can run hdmi, im seriously getting stressed out. the desktop was playing sound just fine a week ago now its broken. Should I buy another sound card or what software should I use so the audio can work.