Wireless Mice and Keyboards from Logitech- How to make them work with the receiver dongle

The general rule technical people learn is that a wireless mouse or keyboard or combination that communicates with that little device you plug into the a USB port of your computing device- the receiver- will only work between one unique wireless device and its receiver.  This means that if you lose the little receiver, you might as well throw away the mouse or keyboard; they won't work with another receiver. 

This is not true for logitech devices where the device and the receiver have a small orange asterisk-like symbol on them.  Any input device can communicate to any such receiver.  In fact, several input devices can simultaneously use the same receiver.  Logitech calls this "Unifying" and devices that can do this are called Unifying devices. 

This might seem like an irrelevant issue to most of you, but I my experience is that it is a common problem. 

Logitech has a small application you have to use to connect any the two devices.  It is called Logitech Unifying Multi-Connect Utility.  Find it here:  https://support.logitech.com/en_us/product/unifying/downloads.  This link is for the Windows and Apple versions.  If you have a Unix-based device, then read this article:  https://askubuntu.com/questions/113984/is-logitechs-unifying-receiver-supporteds

I've ripped off some instructions on how to use the app: 

One leave-in wireless receiver connects multiple compatible devices to a notebook computer. The tiny receiver stays in a notebook USB port and pairs with wireless peripherals at the office, at home, and in a laptop bag. Connect to up to six (6) compatible devices without fumbling with cords or multiple receivers. For more information, please visit https://www.logitech.com/unifying. For identification of Unifying products, please look for the Unifying icon on mice or keyboards and wireless receivers. Logitech Unifying Multi-Connect Utility It’s simple and fast to set up devices for the whole office using the Logitech Unifying Multi-Connect Utility designed specifically for the IT professional. Please speak with your reseller to get a copy of the Utility. Setup instructions of Logitech Unifying Multi-Connect Utility: 

Step 1 Launch the Logitech Unifying Multi-Connect Utility. 
Step 2 Plug in one Unifying receiver; remove any extra receiver from the USB port. 
Step 3 Click "Configure" to select the number of devices you would like to pair with the Unifying receiver. You can select any combination, up to a total of six (6) devices. 
Step 4 Follow the on-screen instructions. 
Step 5 When finished, click "Exit" when pairing all the devices to the receiver is done. If you would like to pair other Unifying devices to a different receiver, do not exit. Remove the first paired wireless receiver and plug in the next Unifying receiver. Repeat from Step 3. 

Trouble Shooting: Clear receiver. Start over from Step 3.