Microsoft 
Logitech unifying software download It is a free program for Logitech Unifying buyers. This software allows you to add other compatible mice, keyboards and number pad to the Unifying receiver.
What is a Logitech Unifying receiver?
The Unifying receiver is designed to give notebook users an easy, convenient and clutter-free way to connect all compatible mice and keyboards to their computers.
You can keep a single Unifying receiver permanently plugged into your computer instead of dealing with multiple receivers, each of which is likely to get lost. Whichever you need whenever, all your compatible wireless mice and keyboards are always ready to go.
