A BSOD stop code is the alphanumeric identifier Windows shows on a blue screen to name the exact type of kernel fault, and most stop codes trace back to one of three things: a faulty driver, defective RAM, or corrupt system files. The code appears as a readable name such as MEMORY_MANAGEMENT and a hex value such as 0x0000001A, and you can read it again after a restart in Event Viewer or a minidump. The code names the class of fault, not always the exact part, so you use it as the starting point and apply the fix that matches its group: drivers, memory, disk and boot, or power.
What Is a Stop Code?
A stop code is a kernel error identifier that Windows assigns when it halts to prevent data loss, shown both as a readable name and a hexadecimal bug-check value. The points below explain what the code is made of.
- A named error type. The text name, such as MEMORY_MANAGEMENT, describes the class of fault the kernel detected.
- A hexadecimal value. A value such as 0x0000001A maps to the same error in logs and on the Microsoft Learn bug-check reference.
- Four bug-check parameters. These give the precise address or condition that triggered the stop, and their meaning differs per code.
- A possible driver name. Many screens list the failing .sys file under “What failed,” which names the component at fault.
Because the code names a class of fault rather than a single broken part, it points you to the right area to investigate. The full crash workflow that surrounds any code is covered in the guide to fixing the Blue Screen of Death.
Common Windows Stop Codes and Their Fixes
The table below lists the most common Windows stop codes with the likely cause and the first fix to apply for each. Match the code shown on the screen to its row before changing anything, then apply only that fix.
| Stop code | Hex value | Likely cause | First fix |
|---|---|---|---|
| CRITICAL_PROCESS_DIED | 0x000000EF | Corrupt system files or a bad update | Run SFC and DISM, undo the recent update |
| SYSTEM_SERVICE_EXCEPTION | 0x0000003B | Faulty driver or corrupt system file | Update drivers, run SFC and DISM |
| KERNEL_SECURITY_CHECK_FAILURE | 0x00000139 | Incompatible driver or corrupt data structure | Update drivers, run SFC, then test RAM |
| DRIVER_POWER_STATE_FAILURE | 0x0000009F | A driver mishandled a sleep or wake transition | Update or roll back the named driver |
| IRQL_NOT_LESS_OR_EQUAL | 0x0000000A | Faulty driver or bad RAM hitting wrong memory | Update drivers, then test RAM |
| PAGE_FAULT_IN_NONPAGED_AREA | 0x00000050 | Defective RAM or a faulty driver | Test RAM, update or roll back drivers |
| MEMORY_MANAGEMENT | 0x0000001A | Defective RAM or a faulty driver | Run Windows Memory Diagnostic |
| VIDEO_TDR_FAILURE | 0x00000116 | Graphics driver timeout or GPU fault | Clean reinstall the graphics driver |
| DPC_WATCHDOG_VIOLATION | 0x00000133 | Outdated SSD firmware or storage driver | Update SSD firmware and SATA driver |
| INACCESSIBLE_BOOT_DEVICE | 0x0000007B | Storage driver conflict or disk corruption | Roll back storage changes, run chkdsk |
Two of these have their own step-by-step repairs: the steps to fix CRITICAL_PROCESS_DIED and to fix KERNEL_SECURITY_CHECK_FAILURE go deeper than the first fix listed here.
How Do You Find Your Stop Code?
The stop code appears on the blue screen, but Windows also records it so you can read it after the system restarts. Work through these in order.
- Read it on the blue screen. Note the stop-code name and any file listed under “What failed,” and scan the QR code to open the Microsoft support page for that code.
- Check Event Viewer. Open Event Viewer, expand Windows Logs, select System, and find the BugCheck error, which records the code after a restart.
- Open the latest minidump. Open the newest file in C:\Windows\Minidump with BlueScreenView to read the code and the Caused By Driver, the failing .sys file.
- Look it up on Microsoft Learn. Search the bug-check reference for the name or the 0x value to get the official description and the four parameter meanings for that code.
For deeper analysis, install the Windows Debugging Tools, open the dump in WinDbg, and run !analyze -v to print the probable cause and the failing module. The four bug-check parameters confirm whether a fault is a read or write error, a timeout, or an unhandled exception, which guides the choice between a memory test and a driver replacement.
Group the Codes by Root Cause
Every common code falls into one of four groups, and the group tells you which fix to try first. The cards below sort the codes by the part they point to.
Is the Code Hardware or Software?
Classifying a stop code as hardware or software directs the fix toward component tests or driver and file repairs. A few checks separate the two.
- Same code, no driver named. A consistent code such as WHEA_UNCORRECTABLE_ERROR with no .sys file points to hardware.
- Different codes each crash. Varying stop codes across crashes usually indicate failing RAM or a failing drive corrupting different data.
- One code tied to one driver. The same .sys file across crashes points to a single software driver to update or remove.
- Crashes only under load or heat. Stop errors that appear during gaming or heavy work point to overheating or a marginal power supply.
When minidumps do not name a driver, Driver Verifier can force the offender to surface. Create a System Restore point, type verifier in Windows Search, choose Create standard settings, select all non-Microsoft drivers, and restart. After the next crash, read the named driver in the minidump, then run verifier /reset to turn it off. If the PC cannot boot, enter Safe Mode and run verifier /reset there.
Stop Codes That Point to Failing Hardware
A small set of codes points almost always to hardware rather than software, so these lead straight to component tests. The codes below indicate physical faults.
- WHEA_UNCORRECTABLE_ERROR (0x00000124). The Windows Hardware Error Architecture reported an uncorrectable fault in the CPU, memory, or bus, often from overheating or instability.
- CLOCK_WATCHDOG_TIMEOUT (0x00000101). A processor core stopped responding to interrupts, pointing to a CPU fault or an unstable overclock.
- MACHINE_CHECK_EXCEPTION (0x0000009C). The CPU detected an internal hardware error, commonly from heat, power, or a failing processor.
- UNEXPECTED_KERNEL_MODE_TRAP (0x0000007F). A hardware trap such as a divide error often indicates faulty RAM or an unstable overclock.
For each of these, reset any overclock to stock, confirm temperatures, run Windows Memory Diagnostic, and verify the power supply before suspecting software. Because faulty memory triggers several codes, the explanation of how RAM works helps confirm a module fault before replacement. A wider catalog of symptoms sits in the guide to common PC problems.
Last Thoughts on BSOD Stop Codes
A stop code is the starting point for every blue screen repair, because the code names the fault and the minidump names the driver behind it. Most codes trace back to a driver, defective RAM, or corrupt system files, so reading the code, looking it up on Microsoft Learn, and applying the matching group fix resolves the crash without trial and error. The code names the symptom, not always the exact part, which is why the general BSOD workflow still sits underneath any single code.
Stop codes are one branch of a much wider set of faults a PC can show. The hub on common PC problems connects this reference to the rest of the diagnostic workflow, from boot failures to overheating.
Key Takeaways:
- A stop code names the class of fault; most trace back to drivers, RAM, or corrupt system files.
- The hex value, such as 0x0000001A, maps the code to the Microsoft Learn bug-check reference.
- Read the code after a restart in Event Viewer (Windows Logs, System, BugCheck) or in a minidump.
- A minidump opened in BlueScreenView or WinDbg names the failing .sys driver behind the crash.
- Group the code as driver, memory, disk and boot, or power, and apply only that group’s first fix.
- Codes such as WHEA_UNCORRECTABLE_ERROR with no driver named point to hardware, not software.
Frequently Asked Questions (FAQs)
What is a BSOD stop code?
A BSOD stop code is the error identifier Windows shows on a blue screen, given as both a name like MEMORY_MANAGEMENT and a hex value like 0x0000001A. It names the type of kernel fault that forced the system to halt, and most codes trace back to a driver, RAM, or corrupt system files.
What is the most common BSOD stop code?
IRQL_NOT_LESS_OR_EQUAL is among the most common, usually meaning a driver or faulty RAM accessed a wrong memory address. CRITICAL_PROCESS_DIED, SYSTEM_SERVICE_EXCEPTION, and MEMORY_MANAGEMENT are also frequent. Update drivers first, then test memory.
Where do I find the stop code after the PC restarts?
Open Windows Event Viewer, expand Windows Logs, select System, and find the BugCheck error. The latest file in C:\Windows\Minidump, opened in BlueScreenView, also shows the code and the failing driver after a restart.
Does the same stop code always have the same cause?
No. A stop code names a class of fault, not one exact part. MEMORY_MANAGEMENT can come from bad RAM or a faulty driver, so the code points you to the right area but not always the exact component. Use the minidump and bug-check parameters to narrow it down.
What does KERNEL_SECURITY_CHECK_FAILURE mean?
KERNEL_SECURITY_CHECK_FAILURE (0x00000139) means the kernel detected corruption of a critical data structure, per the Microsoft Learn bug-check reference. It usually points to an incompatible driver, corrupt system files, or faulty memory. Update drivers, run SFC and DISM, then test RAM.
Which stop codes mean failing hardware rather than software?
WHEA_UNCORRECTABLE_ERROR (0x124), CLOCK_WATCHDOG_TIMEOUT (0x101), and MACHINE_CHECK_EXCEPTION (0x9C) point to a CPU, memory, or power fault, often from heat or an unstable overclock. Reset any overclock, check temperatures, test RAM, and verify the power supply before suspecting software.
