0x00000055 DATA_COHERENCY_EXCEPTION: Causes and Troubleshooting

Quick Answer

The 0x00000055 DATA_COHERENCY_EXCEPTION is a Windows bug check (Blue Screen of Death or BSOD) that appears very infrequently. Microsoft identifies the stop code but does not provide a detailed public explanation of its underlying cause. The recommended diagnostic approach is to examine the crash information and determine what triggered the failure.

If this error appears on your computer, begin by disconnecting recently added hardware, checking for recent driver or software changes, installing appropriate Windows updates, and examining crash records. If the error repeats, investigate system stability and hardware diagnostics before attempting advanced repairs.

What Does DATA_COHERENCY_EXCEPTION Mean?

DATA_COHERENCY_EXCEPTION is the name associated with Windows bug check 0x00000055. A bug check occurs when Windows encounters a serious kernel-level problem and stops normal operation.

Microsoft describes this particular bug check as very rare. Its public documentation recommends using the Windows debugger's !analyze extension to obtain information that may help identify the root cause.

Symptoms of the 0x00000055 Error

Depending on the circumstances, a computer experiencing this bug check may exhibit one or more of the following symptoms:

• A blue screen displaying the DATA_COHERENCY_EXCEPTION stop code.
• An unexpected Windows restart or shutdown.
• A crash during startup or while Windows is running.
• Repeated system crashes after a recent hardware, driver, or software change.
• Crash dump files created during a system failure, if dump collection is configured and succeeds.

These are general symptoms associated with system crashes, not a list of symptoms uniquely established for bug check 0x55.

Possible Causes

The exact cause cannot be determined from the stop code alone. Windows crashes can involve hardware, drivers, software, or system-level faults. The following are reasonable areas to investigate, not confirmed causes specific to every DATA_COHERENCY_EXCEPTION incident.

Do not replace hardware, reinstall Windows, or modify firmware solely because the code is 0x00000055. Use diagnostic evidence to narrow down the cause first.

Before You Begin

• Back up important files if Windows still starts reliably.
• Record the exact stop code and any driver or module name displayed on the crash screen.
• Note when the crash occurs, such as during startup, gaming, idle operation, or after connecting a device.
• Identify recent hardware installations, driver updates, Windows updates, and configuration changes.
• If the computer is managed by an organization, consult the IT administrator before changing drivers, firmware, or security settings.

How to Fix DATA_COHERENCY_EXCEPTION (0x00000055)

1. Restart Windows and Check Whether the Error Returns

If the computer has restarted successfully, save your work and observe whether the error occurs again. A single crash does not necessarily establish a persistent hardware fault.

1. Restart the computer normally if Windows allows it.
2. Use the computer under normal conditions and note any recurring crash pattern.
3. If the same stop code returns, continue with the diagnostic steps below.

Expected result: Windows remains stable without another unexpected shutdown. If the error returns, record the circumstances and continue troubleshooting.

2. Disconnect Recently Added Hardware

New or incompatible hardware and its drivers can contribute to Windows stop errors. Disconnect nonessential peripherals added shortly before the problem began.

1. Shut down the computer.
2. Disconnect nonessential external USB devices, docks, adapters, and other recently added peripherals.
3. Restart Windows and check whether the crash recurs.
4. Reconnect devices one at a time if the system becomes stable.

Do not disconnect essential storage devices while the computer is running. For internal components, use a qualified technician if you are not experienced with hardware installation and electrical safety.

Expected result: If the problem stops after a particular peripheral is removed, investigate that device, its driver, its connection, and compatibility. This observation is evidence, not definitive proof of the cause.

3. Check Device Manager and Recent Driver Changes

Device Manager can help identify devices reporting driver or hardware problems.

1. Right-click Start and open Device Manager.
2. Look for devices displaying a warning symbol.
3. Review devices and drivers that were recently installed or updated.
4. Obtain compatible drivers from Windows Update or the computer or device manufacturer's official website.
5. If the crash began immediately after a driver update, consider the Roll Back Driver option when available.

To roll back a driver, open the affected device's Properties, select the Driver tab, and choose Roll Back Driver if the option is available. Restart Windows and test again.

Expected result: The device operates normally and the system no longer crashes. If the error continues, restore the previous configuration if necessary and investigate the crash dump.

4. Install Appropriate Windows Updates

Windows updates can include reliability fixes and compatible driver updates. Installing updates is a general troubleshooting measure for recurring stop errors, although it is not a guaranteed fix for this specific bug check.

1. Open Settings.
2. Navigate to Windows Update. In Windows 10, use Settings > Update & Security > Windows Update.
3. Select Check for updates.
4. Install applicable updates and restart the computer if requested.

Use drivers intended for your exact device and Windows version. Avoid third-party driver-updater utilities that cannot establish the correct manufacturer-supported package.

Expected result: Updates install successfully and the computer remains stable. If the stop code returns, continue with system checks and diagnostic evidence.

5. Repair Windows System Files

Windows includes Deployment Image Servicing and Management (DISM) and System File Checker (SFC). These tools can repair certain Windows component and protected system-file problems. They do not directly diagnose every cause of DATA_COHERENCY_EXCEPTION.

Open Command Prompt or Windows Terminal as an administrator. Run the following commands separately, in this order.

Step 1: Repair the Windows component store

DISM.exe /Online /Cleanup-Image /RestoreHealth

This command checks and repairs the online Windows image using available repair sources. An internet connection may be needed when Windows Update supplies the required files.

Step 2: Scan protected Windows system files

sfc /scannow

SFC scans protected system files and attempts to replace corrupted files with valid copies.

Verification: Wait for each command to finish and read its final status. Restart Windows if required, then check whether the crash returns. If both tools complete successfully but the bug check persists, investigate drivers, hardware, and crash dumps instead of repeatedly running the same commands.

6. Run Windows Memory Diagnostics

Memory testing is appropriate when there are signs of RAM instability, unexplained crashes, or other evidence pointing to a memory problem. The 0x00000055 code alone does not prove that RAM is defective.

1. Save all open work.
2. Search Windows for Windows Memory Diagnostic.
3. Open the utility and select the option to restart and check for memory problems.
4. Allow the test to complete.
5. After Windows starts, review the results in Event Viewer under Windows Logs > System. Look for the MemoryDiagnostics-Results entry.

Expected result: The diagnostic reports whether it detected memory errors. If errors are reported, consult the computer or motherboard manufacturer's guidance for further memory testing. A test that reports no errors does not exclude every intermittent hardware problem.

Do not change memory voltage, remove RAM modules, or alter BIOS/UEFI memory settings without appropriate technical knowledge and a clear diagnostic reason.

7. Review Event Viewer for Related Errors

Event Viewer may contain system events recorded around the time of the crash. These events can provide context but do not always identify the root cause.

1. Right-click Start and select Event Viewer.
2. Expand Windows Logs and select System.
3. Review critical and error events at the time of the unexpected restart.
4. Record relevant event sources, IDs, timestamps, and descriptions.
5. Compare the events with recent driver changes, hardware activity, and any available crash dump.

An unexpected shutdown event alone does not identify why Windows crashed. Give more weight to evidence that consistently matches the time and circumstances of the failure.

8. Analyze the Crash Dump with WinDbg

For a recurring DATA_COHERENCY_EXCEPTION, crash dump analysis is one of the most useful next steps. Microsoft's documentation specifically recommends the !analyze debugger extension for investigating this bug check.

Small memory dumps are commonly stored in the following directory:

C:\Windows\Minidump

A complete or kernel memory dump may be stored at another configured location, commonly C:\Windows\MEMORY.DMP. These files might not exist if dump collection is disabled, the crash occurs too early, or Windows cannot write the dump.

1. Locate the available crash dump file.
2. Install and open WinDbg using Microsoft's official debugging tools.
3. Open the dump file in WinDbg.
4. Run the following debugger command in the command window.

!analyze -v

The command requests a more detailed analysis of the bug check and available debugging information.

Review the bug check code, parameters, stack information, and any implicated module. A driver named in the output may be relevant, but it is not automatically the root cause; additional evidence may be necessary.

Expected result: The analysis provides clues that help narrow the investigation. If the output is inconclusive, preserve the dump and relevant system details for an experienced Windows debugger or support technician.

Advanced Troubleshooting

Start Windows in Safe Mode

If Windows repeatedly crashes during normal startup, Safe Mode can help determine whether the issue depends on components loaded during a normal boot. Safe Mode is a diagnostic environment, not a guaranteed repair.

Access Windows Recovery Environment using the supported recovery options for your device, then navigate to Troubleshoot > Advanced options > Startup Settings > Restart. Select the appropriate Safe Mode option when the Startup Settings screen appears. The available options can vary by Windows configuration.

If Windows is stable in Safe Mode, investigate recently installed drivers, startup software, and other components that differ from normal startup. If crashes continue, hardware or lower-level system problems remain possible.

Undo Recent System Changes

If the first crash occurred directly after a known software or driver change, consider reversing that change before attempting broader repairs.

• Roll back a recently updated driver if the option is available.
• Uninstall a recently added application if there is a credible connection to the crash.
• Consider System Restore when an appropriate restore point exists.
• Restore BIOS/UEFI settings to a known stable configuration only when you understand the changes that were made and have the manufacturer's guidance.

Before using System Restore or other recovery options, review the potential effects on applications, drivers, settings, and files. Back up important data whenever possible.

When to Seek Hardware or Professional Support

Escalate the issue when the computer repeatedly crashes, memory diagnostics report errors, storage or hardware diagnostics identify faults, or crash dump analysis points to a persistent low-level problem.

Provide the technician with the exact stop code, crash timestamps, dump files where appropriate, diagnostic results, hardware configuration, and a record of recent changes. This information is more useful than replacing components based on the stop code alone.

How to Verify the Fix

After applying a relevant change, restart the computer and test the activity that previously triggered the crash.

• Confirm Windows starts normally.
• Check whether the same 0x00000055 stop code returns.
• Review new Event Viewer entries and crash dumps if another failure occurs.
• Confirm that devices and applications operate normally.
• Keep a record of the change that was made and the result.

If the computer remains stable over normal use, the change may have resolved the issue. A short period without a crash does not prove the underlying cause has been conclusively identified.

Prevention

• Install Windows updates and manufacturer-supported drivers appropriate for your hardware.
• Obtain software and drivers from trusted official sources.
• Avoid unstable overclocking or memory settings.
• Investigate recurring crashes promptly and preserve useful diagnostic records.
• Maintain regular backups of important files.
• Keep adequate free storage space and follow manufacturer guidance for system maintenance.

Frequently Asked Questions

What is error code 0x00000055?

It is the Windows bug check named DATA_COHERENCY_EXCEPTION. Microsoft documents it as a very rare bug check and recommends debugger analysis to help determine its root cause.

Does DATA_COHERENCY_EXCEPTION mean my RAM is faulty?

No. The stop code alone does not establish that RAM is defective. Memory diagnostics can help investigate a suspected memory problem, but driver, software, and other hardware issues may also need consideration.

Can a driver cause the 0x00000055 blue screen?

A driver is one possible area to investigate when troubleshooting a Windows crash, especially if the issue began after a driver change. However, Microsoft does not identify a single driver-related cause as universal for this bug check.

Can SFC and DISM fix DATA_COHERENCY_EXCEPTION?

They can repair certain Windows component and system-file problems. They will not resolve every hardware, driver, or kernel-level fault, so persistent crashes require further diagnosis.

Is DATA_COHERENCY_EXCEPTION a virus?

The stop code itself is not proof of a virus or malware infection. Investigate security concerns separately if other evidence suggests malicious activity.

Where can I find the Windows crash dump?

Small memory dumps are commonly located in C:\Windows\Minidump. A configured kernel or complete dump may be located at C:\Windows\MEMORY.DMP. The actual location depends on the system's dump settings and whether Windows successfully created the file.

Should I reinstall Windows to fix error 0x55?

Not as the first step. Begin with safe checks, recent-change analysis, system diagnostics, and crash dump investigation. Consider Windows recovery or reinstallation only when justified by the diagnostic evidence and after protecting important data.

What should I do if the error keeps returning?

Preserve the crash dump, review Event Viewer, investigate recent driver or hardware changes, and run relevant hardware diagnostics. If the root cause remains unclear, seek help from a technician who can analyze the dump using WinDbg.

Conclusion

DATA_COHERENCY_EXCEPTION (0x00000055) is a rare Windows bug check whose precise cause cannot be established from the code alone. Start with safe checks and recent system changes, then use appropriate Windows diagnostics and crash dump analysis to narrow down the problem. Avoid destructive repairs or hardware replacement until the available evidence supports them.

Sources

• Microsoft Learn: Bug Check 0x55 — DATA_COHERENCY_EXCEPTION
• Microsoft Support: Resolving Blue Screen Errors in Windows
• Microsoft Support: Using System File Checker in Windows
• Microsoft Learn: The !analyze Debugger Extension
• Microsoft Learn: Analyze a Kernel-Mode Dump File Using WinDbg
• Microsoft Support: Recovery Options in Windows