I have 5.1, works fine. Set to stereo right now, only two speakers work. Mono isn't available, that was wrong info, sorry.
Open the Realtek Audio Manager, or choose Configure in the image you sent. You should see something like this:
http://i514.photobucket.com/albums/t350/Hamarahakki/Nothingbut51.jpg
Try latest Realtek drivers or, perhaps the ones you received in the first place. A registry check wouldn't be bad, say with CCleaner.
Besides, this Forum isn't f*d at all, kindly to your knowledge.