MACHINE_CHECK_EXCEPTION is a Windows Blue Screen of Death (BSOD) associated with bug check code:

0x0000009C (0x9C)

Microsoft defines MACHINE_CHECK_EXCEPTION as a bug check indicating that a fatal machine-check exception has occurred. A machine-check exception is generated when the processor or hardware platform detects a serious low-level hardware condition that cannot safely be ignored.

Unlike many BSOD errors that originate primarily from software or device drivers, MACHINE_CHECK_EXCEPTION should be treated first as a hardware stability problem.

Possible sources include:

• CPU instability or failure
• CPU overheating
• Incorrect processor voltage
• Overclocking or undervolting
• Unstable RAM
• Motherboard or chipset problems
• BIOS/UEFI configuration problems
• Power delivery or PSU instability
• PCI Express or other system-bus errors
• Hardware compatibility problems
• Firmware or microcode issues

A processor's machine-check mechanism can report not only processor faults but also cache, memory and system-bus errors.

Important: MACHINE_CHECK_EXCEPTION vs WHEA_UNCORRECTABLE_ERROR

This distinction is important on modern versions of Windows.

Historically, Windows used:

MACHINE_CHECK_EXCEPTION – Bug Check 0x9C

On Windows Vista and later, most hardware machine-check conditions are instead reported through:

WHEA_UNCORRECTABLE_ERROR – Bug Check 0x124

Microsoft states that 0x9C was replaced by 0x124 for most circumstances on Windows Vista and later. MACHINE_CHECK_EXCEPTION can still occur in specific situations, including when Windows Hardware Error Architecture (WHEA) has not been fully initialized.

Therefore, if you are troubleshooting a modern Windows 10 or Windows 11 PC, information about WHEA errors and bug check 0x124 may also be highly relevant.

What Is a Machine Check Exception?

Modern processors contain internal hardware-error detection mechanisms.

The processor continuously monitors components and operations such as:

• CPU cores
• CPU cache
• Internal processor buses
• Memory communication
• System buses
• Data integrity
• Certain motherboard/chipset interactions

When the processor detects a serious hardware error, it can raise a Machine Check Exception (MCE).

Windows receives the hardware-error notification and may stop the operating system to prevent continued execution in an unreliable hardware state.

This is why simply reinstalling Windows often does not solve MACHINE_CHECK_EXCEPTION.

Common Symptoms

A computer experiencing MACHINE_CHECK_EXCEPTION may show several different symptoms.

Random Blue Screens

The PC suddenly crashes with:

MACHINE_CHECK_EXCEPTION

or:

Stop Code: MACHINE_CHECK_EXCEPTION

Crashes Under Heavy Load

The BSOD may occur while:

• Gaming
• Rendering video
• Running virtual machines
• Compiling software
• Performing CPU-intensive work
• Running benchmarks
• Copying large amounts of data

Load-related crashes frequently justify checking temperatures, power delivery and CPU/RAM stability.

BSOD During Startup

A severely unstable system may crash:

• During Windows startup
• Immediately after login
• During Windows installation
• Before Windows fully loads

Random Restart Without BSOD

Windows may restart so quickly that the blue screen is not easily visible.

System Freezing

The machine may freeze before eventually restarting.

Main Causes of MACHINE_CHECK_EXCEPTION

1. CPU Overheating

Excessive CPU temperature is one of the first hardware conditions to investigate.

Possible causes include:

• CPU fan failure
• Dust-clogged heatsink
• Improper heatsink installation
• Dried thermal compound
• Failed liquid cooling pump
• Poor airflow
• Excessive CPU voltage
• Aggressive overclocking

Microsoft's guidance for fatal WHEA hardware errors specifically recommends confirming that cooling systems such as fans are functioning.

What to Check

Enter BIOS/UEFI and check CPU temperature.

Also inspect temperatures while Windows is under load using a reputable hardware-monitoring utility supplied by the motherboard/OEM or another trusted diagnostic tool.

If temperature rises abnormally quickly, investigate cooling before continuing stress tests.

2. CPU Overclocking

CPU overclocking is another important cause of machine-check errors.

Examples include:

• Increased CPU multiplier
• Increased BCLK
• Manual voltage tuning
• Aggressive Precision Boost Overdrive settings
• Intel performance tuning
• Automated motherboard overclock profiles

Even an overclock that previously appeared stable can become unstable because of:

• Higher ambient temperature
• Component aging
• BIOS changes
• Memory changes
• Voltage fluctuations

Microsoft specifically recommends disabling overclocking when diagnosing fatal hardware errors.

Solution

Enter BIOS/UEFI and select an option similar to:

Load Optimized Defaults

or:

Load Setup Defaults

or:

Restore Defaults

Save the settings and restart.

Test the computer at completely stock settings.

3. RAM Instability

Memory problems can also contribute to machine-check and WHEA hardware errors.

Possible causes include:

• Defective RAM module
• Incorrect RAM voltage
• Aggressive RAM timings
• Mixed memory modules
• Unsupported memory configuration
• Faulty DIMM slot
• XMP/EXPO instability
• CPU memory-controller instability

Microsoft recommends running system diagnostics to verify that system memory is not defective when investigating fatal WHEA errors.

4. XMP or EXPO Memory Profiles

XMP and EXPO allow memory to operate at performance settings stored in the RAM profile.

Although commonly used, enabling such a profile can expose instability in the:

• RAM
• CPU memory controller
• Motherboard
• BIOS memory training

For troubleshooting purposes, temporarily disable XMP/EXPO and operate the RAM at motherboard defaults.

If MACHINE_CHECK_EXCEPTION disappears, memory configuration becomes a major suspect.

5. BIOS or UEFI Problems

Firmware plays a critical role in initializing:

• CPU
• RAM
• PCIe devices
• Power management
• CPU microcode
• Hardware error reporting

A BIOS issue can therefore contribute to low-level hardware instability.

Recommended Actions

Check your PC or motherboard manufacturer's support page for an appropriate BIOS/UEFI update.

Read the release notes carefully.

BIOS updates may include:

• CPU compatibility improvements
• CPU microcode updates
• Memory compatibility improvements
• Stability improvements
• PCIe fixes
• Security updates

Warning: Never interrupt a BIOS update. A failed firmware update can make the motherboard unbootable.

6. Incorrect CPU Voltage

Machine-check errors can occur when the processor does not receive stable voltage.

This may happen because of:

• Manual undervolting
• Excessive overvolting
• Incorrect BIOS configuration
• Motherboard VRM problems
• Aggressive performance tuning

If voltage settings were manually modified, return them to Auto/default during troubleshooting.

7. Power Supply Problems

A failing or inadequate PSU can create instability that resembles CPU, GPU or motherboard failure.

Possible symptoms include:

• BSOD during gaming
• Restart under heavy load
• Sudden shutdown
• MACHINE_CHECK_EXCEPTION
• WHEA errors
• GPU crashes

Check:

• PSU wattage
• PSU age and quality
• CPU EPS power connectors
• GPU power connectors
• Motherboard ATX connector
• Loose cables
• Burn marks or damaged connectors

Do not open the PSU itself; dangerous voltages can remain inside even after disconnection.

8. Motherboard Problems

The motherboard can indirectly generate conditions resulting in machine-check exceptions.

Potential areas include:

• VRM
• CPU socket
• Chipset
• DIMM slots
• PCIe slots
• BIOS
• Power circuitry

For Intel LGA platforms, inspect the CPU socket carefully for damaged or bent contacts if hardware has recently been removed or replaced.

For other socket types, inspect the CPU/socket according to the manufacturer's service procedure.

9. CPU Failure

Although processors generally have low failure rates, CPUs can fail.

Possible indicators include:

• Persistent machine-check errors at BIOS defaults
• Failure during CPU stress testing
• Errors across different RAM configurations
• Crashes after motherboard/PSU/RAM have been verified
• Processor-specific WHEA records
• Increasing instability over time

Before replacing the processor, rule out cooling, BIOS, motherboard, RAM and power delivery.

10. PCI Express or Expansion Hardware

Windows hardware-error architecture can receive errors from PCI Express and I/O hardware as well as processors.

Potential devices include:

• Graphics cards
• NVMe SSDs
• Network cards
• RAID controllers
• Capture cards
• Other PCIe adapters

For troubleshooting, temporarily remove unnecessary expansion hardware.

Step-by-Step MACHINE_CHECK_EXCEPTION Troubleshooting

Step 1 – Undo Recent Hardware Changes

Think about what changed immediately before the problem started.

Examples:

• New RAM
• New CPU
• New graphics card
• BIOS update
• New NVMe SSD
• PSU replacement
• CPU cooler replacement
• Overclocking changes

If possible, return the system temporarily to its last known stable configuration.

Step 2 – Reset BIOS/UEFI

Reset the BIOS to default settings.

Disable temporarily:

• CPU overclocking
• GPU overclocking
• RAM overclocking
• XMP
• EXPO
• Manual CPU voltage
• Undervolting
• PBO tuning
• Custom memory timings

Then test Windows.

This is one of the most valuable early troubleshooting steps.

Step 3 – Check CPU Cooling

Shut down and disconnect the computer.

Inspect:

• CPU fan
• CPU heatsink
• AIO pump if installed
• Dust buildup
• Case fans
• Airflow
• Cooler mounting

If necessary, clean the cooling system and correctly reinstall the CPU cooler using suitable thermal compound.

Step 4 – Test RAM

Windows includes Windows Memory Diagnostic.

Press:

Windows + R

Enter:

mdsched.exe

Select:

Restart now and check for problems

For intermittent memory faults, a longer dedicated memory diagnostic can provide a more thorough test.

If multiple RAM modules are installed, another useful diagnostic technique is testing one compatible module at a time.

Step 5 – Reseat RAM

Power off the computer completely.

Disconnect AC power and follow appropriate electrostatic-discharge precautions.

Remove and reinstall the RAM modules.

If multiple modules exist:

1. Test one module.
2. Test another module.
3. Test different recommended DIMM slots.
4. Check the motherboard manual for correct slot population.

This can help differentiate a bad module from a bad DIMM slot or memory-channel issue.

Step 6 – Update BIOS/UEFI

Obtain firmware only from the computer or motherboard manufacturer's official support site.

Make sure the update corresponds exactly to your model and, where applicable, hardware revision.

After updating, load BIOS defaults and test stability before re-enabling performance tuning.

Step 7 – Update Chipset Drivers

Install current chipset/platform drivers from the system or motherboard manufacturer where appropriate.

Depending on the platform, these may include components relating to:

• Chipset
• Power management
• PCIe
• Storage
• Platform management

A driver is less likely than physical hardware to be the primary cause of a genuine machine-check exception, but software/firmware interaction should not be completely ignored. Microsoft similarly notes that drivers are a less likely but possible contributor to fatal WHEA hardware failures.

Step 8 – Check Windows Event Viewer

Windows Hardware Error Architecture records hardware-error events in the Windows System event log.

Open:

Windows + R

Enter:

eventvwr.msc

Navigate to:

Windows Logs → System

Look around the time of the crash for entries involving:

WHEA-Logger

These records can provide important clues about whether the error relates to a processor, memory hierarchy, PCIe device or another hardware source.

Step 9 – Check Reliability Monitor

Press:

Windows + R

Run:

perfmon /rel

Reliability Monitor provides a timeline of:

• Windows failures
• Application crashes
• Hardware errors
• Driver installations
• Windows updates

Look for changes immediately before MACHINE_CHECK_EXCEPTION started.

Step 10 – Check Windows Minidumps

Crash dumps may be stored in:

C:\Windows\Minidump

and:

C:\Windows\MEMORY.DMP

If no dump exists, verify Windows crash-dump configuration.

Dump analysis is particularly valuable when MACHINE_CHECK_EXCEPTION repeatedly occurs.

Advanced Diagnosis with WinDbg

IT professionals can use Microsoft's WinDbg debugger to inspect the crash dump.

A common starting command is:

!analyze -v

For modern WHEA bug check 0x124, Microsoft documents the use of the WHEA error record and the debugger command:

!errrec <address>

The error record can provide considerably more detail about the underlying hardware condition.

Do not automatically assume that a Microsoft kernel module displayed in a crash dump is defective. Modules such as the HAL may simply be involved in reporting the hardware failure.

Step 11 – Run System File Checker

Although MACHINE_CHECK_EXCEPTION is primarily hardware-oriented, checking Windows system files is reasonable after hardware stability has been addressed.

Open Command Prompt or Windows Terminal as Administrator and run:

sfc /scannow

Restart after completion if repairs are performed.

Step 12 – Run DISM

On supported Windows versions, run:

DISM /Online /Cleanup-Image /RestoreHealth

After DISM completes, run:

sfc /scannow

These commands repair Windows component-store and protected-system-file corruption, but they cannot repair defective physical hardware.

Step 13 – Check Storage

Storage problems are less characteristic than CPU/RAM/power problems for a machine-check exception, but storage and PCIe hardware should still be considered when evidence points in that direction.

Check SMART/health information using the SSD/HDD manufacturer's diagnostic utility where available.

You can also run:

chkdsk C: /scan

For repairs that require the volume to be offline, Windows may request a restart.

Back up important data before intensive disk troubleshooting if storage failure is suspected.

Step 14 – Test Without the Dedicated GPU

If the processor/motherboard supports integrated graphics:

1. Shut down the PC.
2. Remove the dedicated graphics card if appropriate.
3. Connect the monitor to the motherboard video output.
4. Boot using integrated graphics.
5. Test system stability.

If the crashes disappear, investigate:

• GPU
• GPU power delivery
• PSU
• PCIe slot
• GPU drivers

Step 15 – Check Power Connections

Power off the system and inspect:

• 24-pin motherboard connector
• CPU EPS connector
• GPU power connectors
• Modular PSU connections
• SATA power connections

Loose or poorly seated power connectors can produce difficult-to-diagnose instability.

Step 16 – Test the PSU

If the problem occurs primarily under heavy CPU/GPU load, power delivery deserves special attention.

The best practical test is often a known-good, correctly rated PSU.

Do not rely solely on a basic PSU tester because intermittent voltage instability may occur only under real system load.

Step 17 – Test Minimum Hardware Configuration

For difficult cases, reduce the system to essential hardware:

• Motherboard
• CPU
• CPU cooler
• One RAM module
• Boot drive
• Integrated graphics where available
• Keyboard and monitor

Disconnect unnecessary:

• USB devices
• PCIe cards
• Additional drives
• RGB controllers
• External peripherals

If the system becomes stable, reconnect devices gradually.

If MACHINE_CHECK_EXCEPTION Appears After Installing RAM

Try this order:

1. Disable XMP/EXPO.
2. Load BIOS defaults.
3. Verify RAM compatibility.
4. Test each DIMM individually.
5. Test recommended motherboard slots.
6. Update BIOS.
7. Run extended memory testing.
8. Inspect the CPU/socket if a memory channel behaves abnormally.

If MACHINE_CHECK_EXCEPTION Appears After CPU Upgrade

Check:

• BIOS CPU support
• BIOS version
• CPU installation
• CPU power connector
• Cooler mounting pressure
• CPU temperature
• Socket contacts
• RAM compatibility
• PSU capacity

A motherboard may physically accept a CPU while still requiring a newer BIOS before that processor is properly supported.

If MACHINE_CHECK_EXCEPTION Happens While Gaming

Gaming can simultaneously stress:

• CPU
• GPU
• RAM
• PCIe
• PSU
• Cooling

Therefore gaming-related MACHINE_CHECK_EXCEPTION does not automatically mean the GPU is faulty.

Start by returning CPU, GPU and RAM to stock settings, then monitor temperatures and test the hardware subsystems individually.

If MACHINE_CHECK_EXCEPTION Happens During Windows Installation

A BSOD during a clean Windows installation is particularly significant.

If the system crashes even while Windows is being installed, investigate hardware and firmware aggressively:

• Reset BIOS.
• Disable XMP/EXPO.
• Test RAM.
• Check CPU temperature.
• Update BIOS if appropriate.
• Disconnect unnecessary hardware.
• Test the SSD.
• Test the PSU.
• Inspect CPU/socket/motherboard.

Repeated hardware-related BSODs during installation make ordinary installed-software corruption a much weaker explanation.

Can Reinstalling Windows Fix MACHINE_CHECK_EXCEPTION?

Sometimes, but it should not be the first assumption.

A clean installation can help if the actual trigger involves:

• Corrupted system files
• Problematic drivers
• Incorrect low-level software
• Damaged Windows installation

However, a genuine processor-reported machine-check condition is commonly hardware or firmware related.

If MACHINE_CHECK_EXCEPTION continues after a clean installation, focus heavily on:

CPU → cooling → RAM → BIOS → motherboard → PSU → PCIe hardware

Recommended Diagnostic Order

For technicians, the following sequence is efficient:

1. Reset BIOS to defaults

↓

2. Disable all overclocking/XMP/EXPO/undervolting

↓

3. Check CPU temperature and cooling

↓

4. Test RAM

↓

5. Review WHEA/System events

↓

6. Analyze crash dumps

↓

7. Update BIOS and chipset/platform drivers

↓

8. Test minimum hardware configuration

↓

9. Test PSU

↓

10. Test motherboard/CPU

This order reduces the risk of wasting time reinstalling Windows when the underlying issue is physical hardware instability.

MACHINE_CHECK_EXCEPTION Troubleshooting Checklist

Before replacing hardware, verify:

• BIOS reset to defaults
• CPU overclock disabled
• GPU overclock disabled
• XMP/EXPO disabled
• Undervolting disabled
• CPU temperature normal
• CPU fan/pump functioning
• RAM tested
• RAM reseated
• BIOS updated if appropriate
• Chipset/platform drivers checked
• WHEA events reviewed
• Crash dump analyzed
• PSU connections checked
• PSU tested if possible
• GPU tested separately
• Extra PCIe hardware removed
• Minimum hardware configuration tested
• CPU/socket inspected if appropriate

When Should Hardware Be Replaced?

Replacement becomes reasonable when testing consistently isolates one component.

Replace or further test RAM when:

• Memory diagnostics repeatedly produce errors.
• One DIMM fails while another works.
• One module consistently causes crashes.

Investigate the PSU when:

• The PC shuts down under load.
• Crashes correlate strongly with CPU/GPU load.
• Known-good PSU testing resolves the problem.

Investigate the motherboard when:

• Multiple known-good components fail only on one board.
• A RAM channel or PCIe slot repeatedly malfunctions.
• VRM or socket damage is visible.
• Stability remains poor with known-good CPU/RAM/PSU.

Investigate the CPU when:

• CPU-specific hardware errors persist at stock settings.
• Cooling is verified.
• RAM and PSU are verified.
• BIOS is correctly configured.
• Motherboard testing does not reveal another cause.

Frequently Asked Questions (FAQ)

1. What does MACHINE_CHECK_EXCEPTION mean?

It means Windows received a fatal machine-check condition from the hardware platform. Microsoft associates it with bug check 0x0000009C.

2. Is MACHINE_CHECK_EXCEPTION a hardware error?

It should primarily be treated as a hardware or low-level firmware stability error. CPU, RAM, cooling, motherboard and power delivery are major areas to investigate.

3. What is the MACHINE_CHECK_EXCEPTION stop code?

The traditional bug check value is:

0x0000009C

or simply:

0x9C

 

4. Can overheating cause MACHINE_CHECK_EXCEPTION?

Yes. Thermal instability can contribute to fatal hardware errors, and Microsoft specifically recommends checking that cooling systems are functioning when troubleshooting related WHEA hardware failures.

5. Can RAM cause this BSOD?

Yes. Memory errors or unstable memory configuration can contribute to machine-check hardware errors.

6. Can XMP cause MACHINE_CHECK_EXCEPTION?

An unstable XMP configuration can contribute to CPU/memory subsystem instability. Disable XMP temporarily when troubleshooting.

7. Can AMD EXPO cause the error?

If the EXPO memory profile is unstable on a particular CPU/RAM/motherboard combination, disabling it is a useful diagnostic step.

8. Can CPU overclocking cause MACHINE_CHECK_EXCEPTION?

Yes. Microsoft recommends disabling overclocking when troubleshooting fatal WHEA hardware errors.

9. Can undervolting cause the BSOD?

Yes. An excessively low CPU voltage can make the processor unstable under particular workloads.

10. Can the power supply cause MACHINE_CHECK_EXCEPTION?

Potentially. Poor or unstable power delivery can destabilize the CPU, GPU and motherboard, especially under load.

11. Can a faulty motherboard cause it?

Yes. Motherboard VRM, chipset, socket, DIMM, PCIe and firmware problems can all contribute to hardware instability.

12. Can a faulty CPU cause MACHINE_CHECK_EXCEPTION?

Yes. A processor beginning to fail can produce machine-check or WHEA hardware errors, although other components should be ruled out before replacing it.

13. Why do I get WHEA_UNCORRECTABLE_ERROR instead?

On Windows Vista and later, most circumstances previously represented by bug check 0x9C are reported through WHEA_UNCORRECTABLE_ERROR (0x124).

14. Where can I find WHEA errors?

Open:

Event Viewer → Windows Logs → System

Look for relevant WHEA-Logger events around the time of the crash. Windows records WHEA hardware events in the System event log.

15. Where are Windows BSOD dump files stored?

Common locations include:

C:\Windows\Minidump

and:

C:\Windows\MEMORY.DMP

depending on the configured dump type.

16. Should I reinstall Windows?

Not initially. Because MACHINE_CHECK_EXCEPTION strongly points toward low-level hardware stability, diagnose hardware, temperatures, BIOS settings and power delivery first.

17. Can BIOS updates fix MACHINE_CHECK_EXCEPTION?

They can help when the underlying issue involves CPU microcode, memory compatibility, firmware bugs or platform stability. Only install firmware intended for the exact motherboard or PC model.

18. Can a graphics card cause machine-check errors?

Potentially, particularly through PCIe or power-delivery problems. However, a gaming-related crash does not prove that the GPU itself is defective.

19. Why does MACHINE_CHECK_EXCEPTION happen only during gaming?

Gaming places simultaneous load on the CPU, GPU, RAM, PCIe subsystem, cooling system and PSU. A marginal component may therefore fail only during gaming.

20. What should I test first?

Start with:

BIOS defaults → disable overclocking/XMP/EXPO → check temperatures → test RAM → inspect WHEA events → analyze crash dumps → test PSU/hardware.

Conclusion

MACHINE_CHECK_EXCEPTION (0x0000009C) is one of the Windows BSOD errors where hardware investigation should take priority over ordinary software troubleshooting.

The error indicates that a fatal machine-check exception has occurred. On modern Windows systems, closely related hardware failures are more commonly reported as WHEA_UNCORRECTABLE_ERROR (0x124).

The most important areas to investigate are:

CPU stability, processor temperature, cooling, RAM, BIOS/UEFI configuration, overclocking, undervolting, motherboard health, PCIe hardware and power delivery.

Do not immediately replace the CPU simply because the error contains the words “Machine Check.” A systematic component-by-component diagnosis is far more reliable.

For advanced troubleshooting, Windows WHEA events and crash-dump analysis can help identify the hardware subsystem reporting the failure.

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