There is a very small plastic piece that looks like the end of a USB cable (because that is what it is!) that comes with the mouse. You stick that plastic in one of your USB slots and the rest should happen automatically. I have never had to download any software. You may have to go to settings and look at the device list to be sure it is listed there. The plastic piece acts as the bluetooth source for the mouse and has to stay in the USB slot-the only disadvantage to this mouse.