Did you look inside first , and see if the front pannel audio line is connected to the audio header on the motherboard?
Check the windows "device manager" for the realtek audio device (sound and video section). In the drivers section of the properties, look at the "driver details".
If the software is installed realtek improperly places all the executables and paths in there, that is one clue to thier software being installed and the location.
If it is drivers only package picked up from MSupdates or off the OS install, it may have operational sound without features.
Because realtek uses "port sence" methods which rely on drivers that are getting info from the hardware, it is possible that the system is not being clued in on the connected item. You then would install the proper driver&software package for the audio chipset. Drivers and software are best aquired via the manufacture of the motherboard who implements that audio chipset, and also supplies drivers/software for the correct audio chip.
Then in Control pannel Sound , in the "playback" and "recording" sections, Right Click and you can observe that items can be hidden. disconnected devices can be shown. Then proceed to double left click on playback and recording devices. For realtek in the "General" tab if an plugged in item is detected, it will then show up in the "Jack Information". This does not require getting to the realtek software, because they show up when the rest of the software is installed in the windows sound tabs.
When the item is connected (or some part of them) they are senced at that port (the hardware thinks something is plugged) This sencing does not always work as planned, it is probably based on seeing resistance there, and not all headphones and mics show the same to the hardware. An example might be (never tested it myself) high ohm headsets might not be detected, and require settings things manually using the software.
In the realtek HD Audio manager, check the Preferances button, on this version it lools like a Gear, there are critical swithes inside there that effect the abilites of the front pannel operations, and even other inputs/outputs that can be used as Recording inputs. Very huge changes via those few switches in there. You of course have to have the software istalled. I just discovered myself how that effects front panel and input capabilites.