To complete HP Printer Setup, start by unboxing the printer and connecting it to a power source. Load paper into the tray and install the ink cartridges. For driver installation, visit 123.hp.com/setup and download the latest software. Follow the on-screen instructions to connect your printer via USB or WiFi. If using wireless setup, ensure your network is stable and enter the correct credentials. Run a test print to confirm successful setup. If issues arise, restart your printer and router or reinstall drivers. Using 123.hp.com/setup ensures a seamless installation process for your HP printer.