0x00000123 CRYPTO_SELF_TEST_FAILURE Blue Screen Error in Windows – Causes and Troubleshooting

Quick Answer

CRYPTO_SELF_TEST_FAILURE (Bug Check 0x00000123) is a Windows Blue Screen of Death (BSOD) error indicating that the Windows cryptographic subsystem failed a mandatory cryptographic algorithm self-test during system initialization.

Cryptographic self-tests help verify that essential cryptographic operations are functioning correctly. When a mandatory test fails during bootstrap, Windows stops the system rather than continuing with a potentially unreliable cryptographic environment.

Microsoft documents this bug check but does not publish a universal repair procedure or a definitive list of causes. Troubleshooting should therefore focus on identifying the underlying system, software, firmware or component issue using crash dumps, recent-change history and Windows diagnostic tools.

What Is CRYPTO_SELF_TEST_FAILURE (0x00000123)?

CRYPTO_SELF_TEST_FAILURE is a Windows kernel bug check, also known as a stop error or system crash. Its hexadecimal bug check value is 0x00000123.

According to Microsoft, this error occurs when the cryptographic subsystem fails a mandatory algorithm self-test during bootstrap.

Cryptographic algorithms are used by operating systems and applications to perform security-related operations, including encryption, decryption, hashing and digital signature verification. Self-tests help establish that the relevant cryptographic implementation is operating correctly.

If a required test fails, Windows may trigger a system bug check to prevent the operating system from continuing in an environment where cryptographic reliability cannot be established.

Important Error Information

Property	Details
Error name	CRYPTO_SELF_TEST_FAILURE
Bug check code	0x00000123
Decimal value	291
Error category	Windows kernel bug check
Subsystem	Cryptographic subsystem
Failure stage	System bootstrap or initialization
Bug check parameters	None documented by Microsoft
Expected result	Windows stops execution and may display a blue screen

What Causes CRYPTO_SELF_TEST_FAILURE?

Microsoft's official documentation identifies the failed cryptographic self-test as the condition that triggers this bug check. It does not establish a comprehensive list of underlying causes.

The following are areas worth investigating during diagnosis. They are potential troubleshooting leads, not confirmed causes of every 0x123 crash.

1. Corrupted or Inconsistent System Components

Damaged Windows system files or inconsistencies in system components may interfere with normal initialization. Check the integrity of Windows files when there is supporting evidence of system corruption.

2. Recent Windows Updates or Software Changes

A crash that begins immediately after an operating system update, security software installation or system configuration change may justify investigating that change. A timing relationship alone does not prove that the update or application caused the failure.

3. Third-Party Security Software

Antivirus, endpoint protection, encryption and other security products may install kernel-level drivers or system components. If the problem started after installing or updating one of these products, investigate its compatibility and update history.

Do not disable security protection permanently. Use the manufacturer's supported repair, update or temporary diagnostic procedure.

4. Firmware or BIOS Configuration

Outdated firmware, an unsuccessful firmware update or unstable BIOS settings may be relevant when the crash occurs during early system initialization. However, there is no Microsoft documentation establishing a direct universal relationship between BIOS versions and this specific bug check.

5. Unstable Hardware or System Configuration

Unstable memory settings, CPU overclocking, undervolting or other non-default hardware configurations can contribute to system instability. Investigate these possibilities if other diagnostic evidence points towards hardware or platform instability.

6. Driver or Kernel Component Conflicts

Recently installed or updated drivers and kernel-level components should be reviewed, particularly if the crash began after a driver change. A crash dump may help establish whether a particular module was involved.

Symptoms of the 0x00000123 Error

Depending on when the failure occurs, users may experience one or more of the following symptoms:

• A Blue Screen of Death displaying CRYPTO_SELF_TEST_FAILURE.
• The stop code 0x00000123 displayed on the blue screen.
• Unexpected system restarts during Windows startup.
• Windows failing to complete the boot process.
• Repeated crashes during system initialization.
• Automatic restart after a system bug check.
• A crash dump being generated, if the system is configured to collect one.

These symptoms are not exclusive to this error. Confirm the actual bug check code rather than diagnosing the problem from a general blue screen appearance.

How to Troubleshoot CRYPTO_SELF_TEST_FAILURE (0x123)

Because this is a relatively specific kernel bug check and its underlying cause is not established by the code alone, use a controlled diagnostic approach. Start with non-destructive checks and preserve crash evidence before making significant system changes.

Step 1: Record the Blue Screen Error Details

Before changing system settings, record the following information:

• The exact stop code: CRYPTO_SELF_TEST_FAILURE.
• The bug check value: 0x00000123.
• Whether the crash occurs during startup, login or normal operation.
• Whether the problem started after a Windows update, driver installation or security software change.
• Whether the computer has experienced other blue screen errors.

Photograph the blue screen if it disappears too quickly to record the information.

Step 2: Check for Crash Dump Files

Windows may generate a memory dump when a bug check occurs. These files can provide useful evidence about the system state at the time of the crash.

Check the following locations:

• C:\Windows\Minidump\ – Small memory dump files, when configured.
• C:\Windows\MEMORY.DMP – Kernel, complete or automatic memory dump, depending on the configured dump type.

If these files exist, preserve them before performing repairs or reinstalling software.

Step 3: Analyze the Dump Using WinDbg

WinDbg is Microsoft's debugging tool for examining Windows crash dumps. It can help identify the bug check, loaded modules and other diagnostic information.

1. Install WinDbg from the official Microsoft source.
2. Open WinDbg.
3. Select the option to open a dump file.
4. Browse to the relevant dump file in the Windows Minidump folder or the location of MEMORY.DMP.
5. Allow the debugger to load the required symbols.
6. Enter the following command in the debugger command window:

!analyze -v

Review the bug check information, module information and available diagnostic details.

You can also use the following command to display the documented description of this bug check:

!analyze -show 0x123

Important: A module appearing in a crash dump does not automatically prove that it caused the failure. Interpret the results in the context of the full dump, system configuration and event history.

For additional guidance, refer to Microsoft's documentation: Analyze a Kernel-Mode Dump File with WinDbg.

Step 4: Review Recent Windows Updates

If the problem started immediately after a Windows update, investigate the update history.

1. Open Windows Settings.
2. Navigate to Windows Update.
3. Open Update history.
4. Review recently installed quality updates, driver updates and other relevant changes.
5. Check whether the timing corresponds with the first occurrence of the crash.

If a particular update is strongly suspected, consult the relevant Microsoft release information and known issues before considering removal.

Uninstalling an update should be a controlled diagnostic step, not an automatic response to every blue screen. Some updates contain important security fixes, and certain updates cannot be removed through normal settings.

Microsoft reference: Windows Update FAQ.

Step 5: Inspect Recently Installed Drivers and Security Software

Review system changes made shortly before the first crash.

1. Open Device Manager by running devmgmt.msc.
2. Expand the relevant hardware categories.
3. Review recently updated device drivers.
4. Check the installation history of antivirus, endpoint protection, encryption and other security applications.
5. Look for manufacturer updates or compatibility notices.

If a specific driver or security product is strongly implicated, use the manufacturer's supported update, repair or rollback procedure.

Do not delete random driver files or manually remove security-related kernel components. Such actions can make Windows unstable or prevent it from starting.

Step 6: Run Windows System File Checker

System File Checker (SFC) checks protected Windows system files and attempts to repair corrupted files using available Windows component-store resources.

Open Command Prompt or Windows Terminal as an administrator and execute:

sfc /scannow

Allow the scan to complete. Review the final result.

Common results include:

• Windows Resource Protection did not find any integrity violations: No protected system-file integrity problems were detected.
• Windows Resource Protection found corrupt files and successfully repaired them: Corruption was detected and repaired.
• Windows Resource Protection found corrupt files but was unable to fix some of them: Additional component-store investigation may be necessary.

An SFC scan checks protected system files. A successful scan does not prove that the cryptographic subsystem, hardware or every third-party component is functioning correctly.

Step 7: Repair the Windows Component Store Using DISM

If SFC reports that some files could not be repaired, investigate the Windows component store using the Deployment Image Servicing and Management (DISM) tool.

Open an elevated Command Prompt or Windows Terminal and execute:

DISM /Online /Cleanup-Image /CheckHealth

This checks whether the component store has already been marked as corrupted.

For a more thorough scan, execute:

DISM /Online /Cleanup-Image /ScanHealth

If repair is required, execute:

DISM /Online /Cleanup-Image /RestoreHealth

After DISM completes successfully, run SFC again:

sfc /scannow

Restart Windows and observe whether the issue returns.

DISM and SFC are general Windows component repair tools. They are not specifically documented by Microsoft as guaranteed fixes for bug check 0x123.

Microsoft reference: Repair a Windows Image.

Step 8: Restore Default BIOS and Hardware Settings

If the computer is using overclocking, undervolting, XMP/EXPO memory profiles or other non-default performance settings, consider investigating them.

1. Restart the computer.
2. Enter BIOS or UEFI setup using the manufacturer's designated startup key.
3. Review any custom CPU, memory or voltage settings.
4. If instability is suspected, restore manufacturer-recommended default settings.
5. Save the changes and restart the computer.

Warning: Before resetting BIOS settings, document the existing configuration. Changes may affect boot mode, storage controller settings, Secure Boot, TPM configuration, virtualization and device encryption.

Do not change SATA or storage controller modes without understanding the existing Windows installation configuration. An incorrect change may make Windows unbootable or trigger a BitLocker recovery request.

If BitLocker or device encryption is enabled, make sure the recovery key is available before making firmware or TPM-related changes.

Step 9: Check BIOS, UEFI and Firmware Updates

Review the computer manufacturer's support website for firmware updates applicable to the exact computer model or motherboard revision.

Before updating firmware:

• Confirm the exact device model and hardware revision.
• Read the manufacturer's release notes and installation instructions.
• Check whether the update addresses a relevant stability or compatibility issue.
• Ensure reliable power during the update.
• Follow any BitLocker suspension or recovery-key instructions provided by the manufacturer.

Never install firmware intended for a different model. An interrupted or incorrect firmware update can make the computer unusable.

Step 10: Investigate Hardware Stability

If the crash continues after software and configuration checks, investigate hardware stability.

Depending on the available evidence, useful checks may include:

• Running the computer manufacturer's built-in hardware diagnostics.
• Testing RAM using an appropriate memory diagnostic utility.
• Reviewing system temperatures and cooling operation.
• Checking power stability and power-supply connections on desktop systems.
• Reviewing processor and motherboard diagnostic information.

Do not assume that RAM, the processor or the motherboard is defective solely because a 0x123 bug check occurred. Hardware replacement should be based on diagnostic evidence.

Step 11: Use Windows Recovery Environment if Windows Cannot Start

If the computer repeatedly crashes before reaching the desktop, use Windows Recovery Environment (Windows RE) to access supported recovery options.

Depending on the Windows version and system configuration, Windows RE may be accessible through automatic recovery after failed startup attempts or through Windows installation or recovery media.

Available options may include:

• Startup Repair: Attempts to diagnose and repair certain startup problems.
• Startup Settings: Provides options such as Safe Mode when supported.
• Uninstall Updates: Allows removal of certain recently installed updates.
• System Restore: Restores system configuration to an available restore point.
• Command Prompt: Provides access to supported diagnostic and recovery commands.

Safe Mode can help investigate whether a recently installed driver or third-party application is contributing to the problem. However, because this bug check is associated with a cryptographic self-test during bootstrap, Safe Mode may not bypass the failure.

Before using recovery options, consider data protection and BitLocker recovery requirements.

Microsoft reference: Windows Recovery Environment.

How to Identify Whether the Problem Is Software or Hardware Related

The bug check code identifies the failed cryptographic self-test, but it does not independently identify the defective component. Use the following evidence to guide further investigation.

Observation	Recommended Investigation
Crash started after a security software update	Review the product's driver and update history; consult its vendor.
Crash started after a Windows update	Review update history and applicable Microsoft release information.
Crash started after a BIOS change	Review the changed settings and test manufacturer-recommended defaults.
Multiple different bug check codes occur	Examine all available crash dumps and investigate broader system instability.
Hardware diagnostics report errors	Follow the manufacturer's diagnostic and repair recommendations.
Crash dumps repeatedly identify a particular third-party component	Investigate that component using its vendor's supported troubleshooting process.
No clear software or hardware evidence is available	Collect additional dumps, event information and system configuration details.

These observations help prioritize diagnostic work. None of them alone establishes the cause of CRYPTO_SELF_TEST_FAILURE.

How to Prevent Future CRYPTO_SELF_TEST_FAILURE Errors

Although this particular bug check does not have a single documented prevention method, the following practices help maintain Windows system stability:

• Install Windows updates from trusted and supported sources.
• Use compatible, manufacturer-provided device drivers.
• Keep security applications updated and supported.
• Avoid unnecessary kernel-level utilities and untrusted system modifications.
• Avoid unstable CPU and memory overclocking configurations.
• Follow manufacturer instructions when updating BIOS and firmware.
• Maintain reliable backups of important files.
• Keep BitLocker recovery information accessible before firmware changes.
• Preserve crash dumps when recurring blue screen errors occur.
• Investigate repeated crashes instead of repeatedly restarting the computer without diagnosis.

Frequently Asked Questions (FAQs)

1. What does CRYPTO_SELF_TEST_FAILURE mean in Windows?

It means that the Windows cryptographic subsystem failed a mandatory algorithm self-test during bootstrap. Windows identifies this condition using bug check code 0x00000123.

2. Is error 0x00000123 a hardware or software problem?

The error code alone does not establish whether the underlying problem is hardware-related or software-related. Investigate crash dumps, recent driver and software changes, firmware configuration and hardware diagnostic results.

3. Can CRYPTO_SELF_TEST_FAILURE be caused by antivirus software?

Security software is a reasonable area to investigate if the problem began after its installation or update, especially when it installs kernel-level components. However, Microsoft does not identify antivirus software as a universal or confirmed cause of this bug check.

4. Does CRYPTO_SELF_TEST_FAILURE mean Windows has been hacked?

No. This stop code does not, by itself, indicate a malware infection or unauthorized access. It indicates a failure of a mandatory cryptographic self-test. Security investigations should be based on additional evidence.

5. Can SFC and DISM fix error 0x123?

SFC and DISM can repair certain types of Windows system-file and component-store corruption. They may help if relevant corruption is present, but Microsoft does not document them as guaranteed repairs for CRYPTO_SELF_TEST_FAILURE.

6. Will resetting BIOS fix CRYPTO_SELF_TEST_FAILURE?

It may help investigate instability associated with custom firmware or hardware settings. However, there is no universal guarantee that resetting BIOS settings will resolve this specific bug check. Record existing settings and consider encryption recovery requirements before making changes.

7. What is the difference between 0x00000123 and 0x00000124?

0x00000123 is CRYPTO_SELF_TEST_FAILURE, which identifies a failed mandatory cryptographic self-test during bootstrap. 0x00000124 is WHEA_UNCORRECTABLE_ERROR, which indicates that Windows reported an uncorrectable hardware error through the Windows Hardware Error Architecture. They represent different bug check conditions and require different diagnostic approaches.

8. Where can I find the crash dump file?

Check C:\Windows\Minidump\ for small memory dumps and C:\Windows\MEMORY.DMP for a larger system dump, if configured and generated. Dump files may not exist if Windows was unable to write them or the required dump configuration was not enabled.

9. Can I continue using my computer after this blue screen?

If Windows restarts successfully and the crash does not recur, preserve available diagnostic information and monitor the system. Repeated crashes, startup failures or other abnormal behavior should be investigated before relying on the computer for critical work.

10. When should I contact technical support?

Contact the computer manufacturer or a qualified Windows support professional if the error continues after basic diagnostics, Windows cannot start, hardware diagnostics report failures, or crash dump analysis requires advanced kernel debugging.

Key Takeaways

• 0x00000123 identifies the Windows bug check CRYPTO_SELF_TEST_FAILURE.
• Microsoft documents the failure as a mandatory cryptographic algorithm self-test failure during bootstrap.
• The bug check code does not identify the exact underlying cause.
• Crash dump analysis using WinDbg is an important diagnostic starting point when dump files are available.
• Review recent Windows updates, security software, drivers and firmware changes.
• SFC, DISM, hardware diagnostics and firmware checks may be useful when supported by the diagnostic evidence.
• Avoid unnecessary BIOS changes, driver deletion, Windows resets or hardware replacement without proper investigation.

Official References

1. Microsoft Learn – Bug Check 0x123: CRYPTO_SELF_TEST_FAILURE
2. Microsoft Learn – Bug Check Code Reference
3. Microsoft Learn – Analyze a Kernel-Mode Dump File with WinDbg
4. Microsoft Learn – Repair a Windows Image
5. Microsoft Support – Windows Recovery Environment
6. Microsoft Support – Windows Update FAQ