Before beginning with the downloading process, make sure your printer has a cartridge and the paper tray has paper loaded in it. Now, click Download, and 123.hp.com/setup will automatically fetch your device details, and start downloading the right software for it. Once the download finishes, click the downloaded 123 HP com setup and hit the Run button to begin the installation process. Do as instructed on the screen, and the setup will get successfully installed on your device. For further assistance, you can reach out to HP support technicians at any hour of the day.