How to Fix Windows 11 24H2 BSOD Crashes on Western Digital SN770 & SN580 SSDs: Host Memory Buffer (HMB) Registry Fix & Firmware Guide (2026)

Following the global rollout of the Windows 11 24H2 feature update, millions of PC builders and laptop owners operating popular Western Digital and SanDisk solid-state drives began experiencing catastrophic system instability. Users reported repetitive Blue Screen of Death (BSOD) crashes occurring during game installations, large file unzipping, or even idle desktop states. The primary culprit has been identified as a critical mismatch between Microsoft's updated NVMe storage stack and the controller microcode powering DRAM-less SSDs.

Unlike high-end drives that feature dedicated onboard DRAM cache chips to manage flash translation layer (FTL) mapping tables, DRAM-less drives like the WD_Black SN770 and WD Blue SN580 rely on system RAM via Host Memory Buffer (HMB) technology. When Windows 11 24H2 altered its memory staging parameters, it triggered a cascading buffer overflow that locks the storage controller, forcing the operating system into an immediate kernel panic.

The Root Cause: 200MB HMB Allocation in stornvme.sys

In Windows 11 23H2 and earlier builds, the standard NVMe storage driver (stornvme.sys) allocated a modest 64MB Host Memory Buffer chunk from system RAM for NVMe translation caching. This 64MB threshold aligned perfectly with the internal memory registers of Western Digital's in-house proprietary controller. However, in Windows 11 24H2, Microsoft increased the default HMB allocation pool to 200MB to accelerate high-bandwidth DirectStorage read workloads.

Because the controller firmware on affected Western Digital drives cannot safely handle buffer requests exceeding 64MB, memory page allocations overwrite adjacent controller registers. The drive abruptly disconnects from the PCIe bus, triggering Event ID 129 ("Reset to device, \Device\RaidPort0, was issued") followed immediately by CRITICAL_PROCESS_DIED or KERNEL_DATA_INPAGE_ERROR stop codes.

As documented in the diagnostic matrix above, multiple DRAM-less models across the Western Digital portfolio are susceptible until updated. Fortunately, users can stabilize their systems immediately using a targeted registry workaround before applying permanent firmware.

Immediate Workaround: The Windows Registry HMB Override

If your PC crashes frequently or you need to stabilize the system to download firmware updates, you can instruct the Windows 11 storage stack to cap or disable HMB allocation using the Registry Editor. If your system cannot boot into normal Windows, enter Windows Recovery Environment (WinRE) and launch Safe Mode with Networking:

1. Press Windows Key + R, type regedit, and press Enter to launch the Registry Editor.
2. Navigate to the following registry path:
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\StorPort
3. Right-click on the StorPort folder in the left sidebar, select New → DWORD (32-bit) Value, and name it exactly: HmbAllocationPolicy
4. Double-click HmbAllocationPolicy and configure the value data:
   • Set to 0 to completely disable Host Memory Buffer.
   • Set to 2 to force Windows to respect the conservative 64MB hardware cap.
5. Click OK, close the Registry Editor, and restart your computer.

Applying this registry modification restricts memory requests to 64MB or below, immediately halting the buffer overflow and preventing further BSOD crashes.

The Permanent Fix: Flashing Firmware via Western Digital Dashboard

While the registry modification eliminates crashes, running an NVMe SSD with disabled HMB can slightly reduce burst random write speeds. The permanent solution is flashing the updated microcode released by Western Digital, which enables the controller to gracefully renegotiate 64MB buffer requests with the Windows 11 24H2 driver:

1. Visit the official Western Digital support portal and download the latest version of Western Digital Dashboard (version 4.2.2.5 or higher).
2. Install and launch the application under administrator privileges.
3. Select your affected drive (e.g., WD_Black SN770) from the main overview menu.
4. Navigate to the Tools tab and select Firmware Update.
5. Click Update Firmware and allow the utility to download and write the microcode (e.g., version 731120WD).
6. Shut down your computer completely when prompted, wait 10 seconds for the drive controller to power-cycle, and boot back into Windows.

After completing the firmware update, you can safely delete the HmbAllocationPolicy registry key or leave it configured at value 2, ensuring permanent operating stability across all future Windows 11 cumulative updates.

Verdict: Essential Maintenance for DRAM-Less Storage

The Windows 11 24H2 Western Digital crash serves as an important engineering reminder of the trade-offs inherent in DRAM-less solid-state storage. By leveraging system memory via Host Memory Buffer, manufacturers deliver exceptional price-to-performance value, but they introduce tight coupling between operating system drivers and hardware microcode.

By applying the registry buffer limitation and flashing official Western Digital firmware updates, users can restore complete platform reliability without sacrificing data integrity or performance. For all Windows 11 24H2 systems equipped with WD SN770 or SN580 SSDs, completing this maintenance update is an essential operational requirement.