HP Pro Mini 400 G9 stuck at boot

[m0ck]

Hello HP Support Community,

We have hundreds of HP Pro Mini 400 G9 systems in our office.

Over the past 2–3 months, we have started experiencing a recurring issue where the Pro Mini 400 G9 becomes completely stuck during reboot, either after a manual restart or during Windows Updates.

Instead of displaying the HP BIOS logo, the system gets stuck at the Windows 11 logo and does not respond to any keyboard input (including BIOS/boot menu keys). The only way to recover it is to disconnect the system from power.

In many cases, even after reconnecting the power, the system immediately displays the Windows 11 logo again and becomes stuck in the same state. It may require multiple power disconnect/reconnect cycles before the system boots normally again.

The affected systems have various BIOS versions, ranging from older versions such as 02.18 up to the latest 02.22.01. Disabling Fast Boot does not appear to resolve the issue.

We are trying to determine whether this is a known issue with the Pro Mini 400 G9, possibly related to the BIOS, Windows 11 updates, or hardware/firmware initialization.

Our older systems, including the HP ProDesk 400 G6 and older G5 models, do not exhibit this behavior.

Has anyone else experienced this issue with the Pro Mini 400 G9? Is there a recommended BIOS setting, firmware update, or troubleshooting procedure that can help identify the root cause?

Any information or guidance from HP would be greatly appreciated.

[Hawks_Eye]

Hi @m0ck 

Welcome to the HP Support Community! We're here to help you get back up and running.

Thank you for providing the detailed information. We understand the concern, especially when the behavior is being observed across multiple HP Pro Mini 400 G9 systems and can affect normal restart operations and Windows Update cycles.

Based on the symptoms described, the behavior appears to occur during the transition between firmware initialization and Windows startup rather than within Windows itself, since the system does not return to the HP startup screen and may require complete power removal before normal operation is restored.

To help isolate the root cause on the HP Pro Mini 400 G9, we recommend the following HP-specific checks:

• Ensure all affected systems are running the same BIOS release. Since your fleet contains versions ranging from 02.18 through 02.22.01, standardizing to the latest BIOS version can help eliminate inconsistent firmware behavior.

• In BIOS Setup (F10), load BIOS defaults, save, and retest. This helps verify that a legacy setting or custom configuration is not contributing to the startup sequence.

• Verify that Intel chipset drivers, Intel Management Engine components, and firmware packages are current through HP Image Assistant or the HP support page for the Pro Mini 400 G9.

• Review BIOS settings related to PCIe initialization, USB startup support, and power management. After any change, test several restart cycles rather than only cold boots.

• Run HP PC Hardware Diagnostics UEFI, paying particular attention to memory and storage tests. Intermittent hardware initialization delays can sometimes surface during reboot scenarios rather than during normal operation.

• If BitLocker is enabled, confirm TPM and security-related firmware settings are consistent across affected systems and that no recent security configuration changes were introduced before the issue began.

• Compare one affected Pro Mini 400 G9 with a unit that consistently reboots normally. Pay particular attention to BIOS settings, storage model, memory configuration, and Windows build level.

Since the issue occurs across multiple BIOS revisions, gathering details such as the storage model, Windows 11 build version, and whether the systems are using a standard corporate image can help further narrow down whether the behavior is related to firmware initialization, hardware configuration, or the operating system startup process.

We appreciate the thorough testing already performed, including BIOS updates and Fast Boot verification. Those checks help significantly in narrowing the scope of investigation.

Take care, and have an amazing day!

Regards, 

Hawks_Eye

[m0ck]

Hi Hawks_Eye,

Thank you for the detailed response. We have already performed most of the suggested checks, and based on our testing, the issue appears to be more specific than a BIOS configuration or hardware problem.

A few additional details:

• BitLocker is not used on these systems.

• We tested the RAM and NVMe drives on affected systems and found no hardware problems.

• We use BIOS Configuration Utility 64 (BCU) to apply the factory/default BIOS configuration. The only BIOS setting we intentionally modify is Power On After Power Loss.

• We also manually loaded the BIOS factory defaults on affected systems, but this did not resolve the issue.

• We have compared affected systems with systems that reboot normally. We have not found any meaningful differences in BIOS configuration, hardware configuration, RAM, NVMe drive, or other relevant settings.

• The issue occurs across different BIOS versions, including older versions and the latest 02.22.01.

There is also an important timing detail: the issue only started appearing during the past 2–3 months. These systems were deployed more than 6 months ago and were operating normally before this started happening. This makes a hardware design problem that was present from deployment less likely.

Another important observation is that we have only seen this behavior on systems running Windows 11.

Some of the affected machines encountered the problem specifically while rebooting as part of an SCCM Windows 10 → Windows 11 upgrade. However, the problem is not limited to upgrades — we have also reproduced it on systems with a clean Windows 11 installation.

Interestingly, I have also experienced essentially the same behavior once on my personal HP Elite Mini 800 G9, with a clean Windows 11 installation and all BIOS, drivers, and firmware fully up to date. This makes me wonder whether there could be a broader Windows 11 / HP firmware / platform initialization interaction rather than something specific to our corporate image or SCCM.

The most concerning part is that when the problem occurs, the machine appears to be completely stuck before normal firmware initialization. It remains at the Windows 11 logo, does not respond to F10/F9/Esc or other keyboard input, and sometimes continues to return to the same state even after AC power is restored. Multiple complete power disconnect/reconnect cycles can sometimes be required before it will boot normally.

At this point, we have hundreds of these systems, so we are seeing enough cases to believe this is more than an isolated hardware failure.

Could HP investigate whether there have been any BIOS/firmware changes or known issues introduced in the past few months that could affect Windows 11 reboot/firmware initialization on the Pro Mini 400 G9 (or related HP Mini platforms)?

In particular, it would be useful to know whether HP is aware of any interaction involving recent Windows 11 updates, Intel ME/chipset components, ACPI/power-state transitions, or firmware initialization during a Windows 11 restart.

We are happy to provide additional information, BIOS versions, Windows build numbers, affected machine details, or logs if that would help HP investigate this further.

Thank you.