I have to say I spent about an hour trying to figure out how to use it off a PC. It worked immediately for my Samsung phone, but it refused to produce sound off my PC. After internet-searching for solutions, I made it work. Here is how:
a) Go to http://support.logitech.com/
b) Click on download button for get a zipped file "paring_utility_1.00...zip".
c) Unzip it to your local folder (or just to the desktop).
d) Find Pairing.exe and click it to install.
e) Follow instructions that the software tells you. Basically on the headset's right-ear part, you have to find and press the volume up (+) button and the >> button (fast-forward button) at the same time until the green light on the headset begins to blink fast. When this happens, it is communicating with the PC and the Paring software. You have to follow a couple of more instructions on the software while this is happening. The >> button (fast forward button) on the headset may be hard to find, but it is on the left side of the green light.