1. Introduction
This manual provides essential information for setting up, operating, maintaining, and troubleshooting your HP Pro 400 G9 Mini PC. Please read this manual thoroughly before using your device to ensure optimal performance and longevity. The HP Pro 400 G9 is a compact and powerful desktop computer designed for various computing needs, featuring a 13th Gen Intel Core i3 processor and Windows 11 Pro.

Figure 1: The HP Pro 400 G9 Mini PC, demonstrating its small form factor.
2. Setup
Follow these steps to set up your HP Pro 400 G9 Mini PC:
- Unpack Components: Carefully remove the Mini PC, power adapter, keyboard, and mouse from their packaging.
- Connect Peripherals:
- Connect the included keyboard and mouse to the available USB-A ports on the Mini PC.
- Connect your monitor(s) to the DisplayPort 1.4 or HDMI 2.1 ports using appropriate cables. The Mini PC supports triple 4K display output.
- If using wired network, connect an Ethernet cable to the RJ-45 port.
- Connect Power: Plug the power adapter into the Mini PC's power connector, then plug the power cord into an electrical outlet.
- Power On: Press the power button located on the front of the Mini PC. The system will boot up.
- Initial Windows Setup: Follow the on-screen instructions to complete the Windows 11 Pro setup, including language, region, network connection, and user account creation.

Figure 2: Front and Rear Port Layout. This diagram illustrates the location and type of all available ports for connecting peripherals and power.
3. Operating
Once setup is complete, your HP Pro 400 G9 Mini PC is ready for use. Here are some operational guidelines:
- Power On/Off: Press the power button to turn the PC on. To shut down, click the Start button in Windows, then select Power > Shut down.
- Network Connectivity: The Mini PC supports WiFi 6E and Bluetooth 5.2. To connect to a wireless network, click the network icon in the taskbar and select your desired network. For Bluetooth devices, go to Windows Settings > Bluetooth & devices.
- USB Ports: Utilize the various USB-A and USB-C ports for connecting external drives, printers, and other USB devices. The USB-C port supports 20Gbps data transfer, and some USB-A ports offer 10Gbps.
- Display Configuration: With support for triple 4K displays, you can extend your desktop across multiple monitors for enhanced productivity. Configure display settings via Windows Settings > System > Display.

Figure 3: The Mini PC integrated into a workspace, demonstrating its discreet placement.

Figure 4: User interacting with the HP Pro 400 G9 Mini PC in a professional environment.
4. Maintenance
Proper maintenance ensures the longevity and optimal performance of your HP Pro 400 G9 Mini PC:
- Keep Vents Clear: Ensure that the ventilation openings on the Mini PC are not obstructed. This allows for proper airflow and prevents overheating.
- Clean Regularly: Use a soft, dry cloth to clean the exterior of the Mini PC. For dust accumulation in vents, use compressed air. Avoid liquid cleaners directly on the device.
- Software Updates: Regularly update Windows 11 Pro and device drivers to ensure security, stability, and access to the latest features. Go to Windows Settings > Windows Update.
- Data Backup: Periodically back up important data to an external drive or cloud storage to prevent data loss.
5. Troubleshooting
If you encounter issues with your HP Pro 400 G9 Mini PC, consider the following basic troubleshooting steps:
- No Power: Ensure the power adapter is securely connected to both the Mini PC and a working electrical outlet. Try a different outlet if necessary.
- Display Issues: Verify that monitor cables are securely connected to both the Mini PC and the monitor. Check if the monitor is powered on and set to the correct input source.
- Slow Startup: If the PC takes a while to start up, ensure all Windows updates are installed. Consider checking startup programs in Task Manager and disabling unnecessary ones.
- Peripheral Not Working: Try connecting the keyboard, mouse, or other USB devices to a different USB port. Ensure drivers are up to date.
- No Internet Connection: For Wi-Fi, check if the network is available and you have entered the correct password. For wired connection, ensure the Ethernet cable is properly connected and your router is functioning.
For more complex issues, refer to the HP support website or contact HP customer service.
6. Specifications
Detailed technical specifications for the HP Pro 400 G9 Mini PC:

Figure 5: Overview of key hardware specifications.
| Feature | Specification |
|---|---|
| Processor | 13th Gen Intel Core i3-13100T (4 Cores, 8 Threads, up to 4.2 GHz) |
| Graphics | Integrated Intel UHD Graphics 730 |
| RAM | Up to 64GB DDR5-5200 MHz |
| Storage | Up to 2TB PCIe M.2 SSD |
| Operating System | Windows 11 Pro |
| Wireless Connectivity | WiFi 6E, Bluetooth 5.2 |
| Front Ports | 1x USB-C (20Gbps), 2x USB-A (10Gbps, 1 charging), 1x Headset Combo |
| Rear Ports | 1x HDMI 2.1, 2x DisplayPort 1.4, 1x RJ-45, 1x USB-A (10Gbps), 2x USB-A (5Gbps), 2x USB-A (2.0), 1x Audio-Out |
| Dimensions (W x D x H) | 6.97 x 6.89 x 1.34 inches |
| Weight | Approximately 3.13 lbs (1.42 kg) |

Figure 6: Physical dimensions and weight of the Mini PC.
7. Warranty and Support
Your HP Pro 400 G9 Mini PC is covered by a standard manufacturer's warranty. For specific warranty terms and conditions, please refer to the documentation included with your product or visit the official HP support website.
For technical assistance, driver downloads, or further support, please visit the HP Support Website or contact HP customer service directly.