SOLVED:After months of trying all options : Headphone Not Detected When Plugged in Jock.

After  installing the latest Realtek Software, it still did not work.  Then I browse the folder of the newly installed up dated Realtek Software, run each Executable application (*.exe), then I happened to open DELL AUDIO App. This is the executable file for Dell Audio App : RtkNGUI.exe.  Go to Advance, Select Jock Information. Then the pop up window where  you select options upon plugging your headset appears. This pop up window was gone though it used to work before each time I plugged in the headset. Then select the option for Headphones with Mic or just Headphones.

Finally, I got to listen to my headphone once again, after months of trying all kinds of solutions that did not work.