First and foremost, sorry for the necropost.
Problem:
I own the motorokr S305 bluetooth headset. When I first paired it with my desktop, I could only receive stereo sound; the microphone would not work. I installed the drivers and programs that came with my "Inland bluetooth dongle" and still, only the sound would work. I had even tried using the MicroSoft generic drivers with no avail.
Solution:
I came across a program called "IVT BlueSoleil ver. 6.4.275.0." It was only a trial version, but I just wanted to test whether or not the problem came from my hardware (the headset), or the software.
This program succeeded where the original program failed. It (IVT BlueSoleil ver...) recognized my headset and provided me with two paths to choose from: 1, High-quality stereo sound, or ;2, microphone usage. The latter path indeed allowed the use of a microphone, but at the cost of sound quality.
TL;DR
Moto S305 headset's mic not working.
Download IVT BlueSoleil ver. 6.4.275.0.
Choose either:
1. High-quality sound and no mic.
2. Poor-quality sound WITH mic.
P.S.
The fully licensed program costs 20$ at bluesoleil.com