SenCe, welcome to the Seven Forums.
You can stop playing around with the Realtek controls as there is nothing you can do there to get it to work. Looking at the specs and manual for that headset, it looks like it only uses a single cable for both audio and mic,
and will only work on smartphones and the like that support that sort of thing, your onboard Realtek (and I doubt any sound card either for that matter) doesn't support audio and voice over a single connection.
Looks like either return them for a headset that uses two connections for audio and mic, or pick up a cheap desk mic if you like the sound/fit of the headphones.