I know there's other threads about the headphone jack not working but I can't reply to it and there's no note as to whether it's closed or not. It's ridiculous that I have to google "how to reply to a post in dell".
Anyways, my headphone jack works but if if take it out and plug it again it won't work. The sound doesn't go through the headphone anymore, instead keeps coming from the computer. To get it to work again I have to restart the computer and then have the same issue again if I plug and unplug the headphone jack. I tried other solutions about updating and disabling certain drivers, did not work.
Here's the solution and what the problem was: I had disable everything in "Startup" apps. So I went and "Enable" the realtek HD audio and the Waves Maxxaudio. That solved the problem.
Note: This dell headphone jack reaction is slow compare to other computers. I plug it in and there's always a delay before I hear any sound.