HP Pro Mini 400 G9 Desktop Computer - Compact Windows 11 Pro Mini PC

In this review the HP Pro Mini 400 G9 is presented as a compact desktop for office users and home professionals who need reliable everyday performance without a large tower. The single biggest reason to consider it is the balance of modern connectivity and expandable memory and storage: it ships with Windows 11 Pro and supports up to 64GB DDR5 RAM and up to 4TB PCIe M.2 SSD, which makes it unusually flexible for a mini form factor.

Key Features

• Processor: The Intel Celeron G6900T provides steady basic compute at 2.8 GHz base frequency, suitable for web work, office apps and light multitasking.
• Memory and storage: Support for up to 64GB DDR5 and large PCIe M.2 SSDs means the system can be upgraded to handle heavier multitasking and large local storage needs.
• Operating system: Ships with Windows 11 Pro 64-bit for business features such as BitLocker and domain joining without extra setup.
• Connectivity: Built-in WiFi 6E and Bluetooth 5.3 provide fast wireless networking and peripheral support for modern home and office networks.
• Ports and displays: Three monitor outputs (2x DisplayPort and 1x HDMI) plus multiple USB and a Gigabit Ethernet port make the mini suitable for multi-monitor workstations and docking scenarios.
• Included peripherals: Comes with an HP black wired keyboard and mouse so it is ready to use right away for standard desktop tasks.

Who It's For

The HP Pro Mini 400 G9 is aimed at small business users, administrators, and professionals who need a reliable, space-saving desktop with modern I/O and the ability to scale memory and storage. It is especially useful for multi-monitor desks thanks to its two DisplayPort outputs and HDMI, and for anyone who prefers Windows 11 Pro for management features.

Users who need high-end CPU cores for heavy video editing, 3D rendering, or gaming should look elsewhere; the dual-core Celeron is efficient but not designed for intense single-threaded or multi-threaded workloads. Also note that a PC stand is not included, so those who require a mounting solution will need to purchase one separately.

Pros & Cons

Pros

• Compact footprint with substantial expansion options for DDR5 memory and PCIe M.2 storage.
• Modern connectivity including WiFi 6E, Bluetooth 5.3, USB-C front port and Gigabit Ethernet for flexible network setups.
• Three monitor outputs make it easy to set up a multi-display workstation without adapters.
• Includes wired keyboard and mouse so the system is ready to use out of the box.

Cons

• The Intel Celeron G6900T is suitable for basic productivity but not for demanding compute tasks or heavy content creation.
• No PC stand included, so mounting or specific placement may require an extra purchase.

Specifications

Processor	Intel Celeron G6900T, 2 cores, 2 threads, 2.8 GHz base
Memory	Supports up to 64GB DDR5 RAM
Storage	Up to 4TB PCIe M.2 SSD
Graphics	Intel UHD Graphics 710
Operating System	Windows 11 Pro, 64-bit (English)
Networking	WiFi 6E, Bluetooth 5.3, 1x Ethernet (RJ-45)
Ports	2x DisplayPort 1.4, 1x HDMI 2.1, multiple USB-A, 1x USB-C front, headset combo

Our Verdict

The HP Pro Mini 400 G9 is a smart choice for business desktops and compact workstations that prioritize connectivity, multi-monitor support and upgrade potential. It delivers solid everyday performance with Windows 11 Pro and modern networking, and represents good value for offices that need reliable, easy-to-manage PCs rather than high-end processing power.

Frequently Asked Questions

Does it include a keyboard and mouse?
Yes, it ships with an HP black wired keyboard and mouse included.

Can the memory and storage be upgraded?
Yes, the system supports up to 64GB DDR5 RAM and PCIe M.2 SSDs up to 4TB for increased performance and capacity.

Is a PC stand included?
No, a PC stand is not included and must be purchased separately if needed.