The **HP OfficeJet Pro 9120e** printer setup, including wireless connection, can be started by visiting the official HP setup page at **hp.com/start/ojp9120e** or the related onboarding site for guided instructions[2][4].

To connect your HP OfficeJet Pro 9120e to Wi-Fi, the general steps (also shown in tutorial videos) are:
– On the printer control panel, go to **Menu > Settings > Network > Wi-Fi**.
– Select **Wi-Fi Setup Wizard** and then **Start**.
– Choose your home or office Wi-Fi network from the list.
– Enter the Wi-Fi password using the on-screen keypad.
– Confirm and wait for the connection success message.
– The wireless light (blue) should be on once connected[1].

If your HP OfficeJet Pro 9120e is **offline or not connecting**, you can try these troubleshooting steps:
– Make sure the wireless light on the printer is lit, indicating Wi-Fi is active.
– Check the wireless signal strength and move the printer closer to the router if needed.
– Restart your router, printer, and computer.
– Run the Wireless Network Test from the printer’s Setup > Network menu.
– Confirm your computer is on the same Wi-Fi network as the printer.
– Temporarily disable firewall software to see if it’s blocking printer communications.
– Ensure the printer is set as the default printing device on Windows.
– Verify that the HP Network Devices Support service is running on Windows[3].

For detailed digital setup guides, scanning the QR code from the printer manual or visiting the URL hp.com/start/ojp9120e provides official step-by-step instructions and resources[2][4].

These resources and steps should help you successfully start, set up, and troubleshoot your HP OfficeJet Pro 9120e All-in-One printer.