Once you have chosen the operating system, click to download the driver under the ‘Driver’ heading. Step 2 Go to your printer manufacturer’s Website; in our example, we’re going to HP.com. Click Support & Drivers, select the Download drivers and software button, and type the name and number of your printer into Canon mx870 driver the search bar. Step 2 If your printer has a yellow exclamation-point icon on it, or if it does not appear at all, downloading new drivers is necessary.