BSOD 0x65 (MEMORY1_INITIALIZATION_FAILED): causes and diagnosis

Status / error code:		Category:

Constant name:
Source:		Operating System:
Description: A later memory-manager initialization phase failed during Windows startup.

Could be also:
Constant	Type	OS
ERROR_EXCL_SEM_ALREADY_OWNED	Win32 error	Windows
HTTP_STATUS_SWITCH_PROTOCOLS	HTTP Code	Any
ENETUNREACH	errno	Linux
ETIME	errno	Mac
EADDRNOTAVAIL	errno	Windows

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SYMBOLIC_INITIALIZATION_FAILED	CACHE_INITIALIZATION_FAILED

MEMORY1_INITIALIZATION_FAILED

Memory manager initialization failure for MEMORY1_INITIALIZATION_FAILED

MEMORY1_INITIALIZATION_FAILED is bug check code 0x00000065.

This bug check indicates that the memory manager could not complete a required startup phase. It may involve PFN database setup, paging structures, memory descriptors, low-memory reservations, or platform memory map inconsistencies.

How to read it in a dump

The boot memory map, firmware tables, RAM layout, and paging mode are important.
A hardware memory fault, firmware bug, or incompatible low-level driver can be more relevant than user-mode memory pressure.
The failing subphase on the stack should guide diagnosis.

What to check

Check RAM, firmware memory map, overclocking, hypervisor memory configuration, and recent kernel/driver changes.
Run memory diagnostics after preserving the dump.
For VMs, verify dynamic memory and virtual hardware settings.

References

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