Over the years I've been buying Logitech mouses, therefore I have few Unifying Receivers lying around from previous peripherals. How to check if they working or not? Now today I got me a new mouse and the receiver that come with it works, but only with this particular mouse. If I just plug one of the old ones to my USB port mouse is not reacting. It does not matter if I plug it to the system that runs or if I plug it and then restart the system. It even doesn't runes with my old Logitech master mouse that I'm sure that works cause I just used it the day before but again with the Unifying Receiver that come with the mouse. I thought that any receiver should work if I plug it to USB. In that case, how should I check if the Unifying Receivers I have works, or if I can throw them away?