BSOD 195 (SYSTEM_IMAGE_BAD_SIGNATURE): causes and diagnosis

Status / error code:		Category:

Constant name:
Source:		Operating System:
Description: Windows rejected a system image because its signature or integrity state was invalid.

Could be also:
Constant	Type	OS
ERROR_INVALID_MINALLOCSIZE	Win32 error	Windows

SYSTEM_IMAGE_BAD_SIGNATURE

Bad system-image signature

SYSTEM_IMAGE_BAD_SIGNATURE is bug check code 0x000000C3. This bug check belongs to system image integrity and driver/code signing. It means a boot-critical or kernel-mode image failed a signature/integrity expectation that Windows treats as fatal.

How to read it in a dump

The failing image path, signature status, and load phase are more useful than the numeric code alone.
This can involve kernel-mode code signing, Secure Boot, catalog files, tampering, or a corrupted system image.
It is different from an ordinary application signature warning.

What to check

Identify the image being loaded and verify its catalog/signature.
Check Secure Boot, Code Integrity events, recent driver installs, servicing operations, and disk corruption.
Do not bypass integrity protections before preserving the failing file for analysis.

References

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