To install your HP printer using **123.hp.com**, follow these steps:
1. **Go to the official site** 123.hp.com or 123.hp.com/setup on a supported device (Windows, macOS, or mobile) to begin the setup process[1][3].
2. **Download and install the HP Smart app** as it provides the fastest and easiest printer setup experience. The app is available for Windows, macOS, Android, and iOS[1][3].
3. Make sure your printer is **powered on and connected to the same Wi-Fi network** as your computer or mobile device.
4. Launch the HP Smart app, then **follow the on-screen instructions to detect and install your printer**.
If you encounter issues such as invalid downloads or software not opening, it could be related to your operating system or browser compatibility. For example, older Mac OS like Yosemite may have trouble and might require alternative methods to unzip or run downloads[2].
Be cautious to use only the official HP site (123.hp.com) for downloads and setup. Beware of scam websites impersonating HP’s site that prompt for unsolicited support calls or access[4].
In case you need additional help, the HP Support page provides troubleshooting guides and direct support options by region[1][3].