KERNEL_SECURITY_CHECK_FAILURE (0x139): Causes and Fixes

KERNEL_SECURITY_CHECK_FAILURE (0x00000139)

Stop code 0x00000139, also written 0x139. Here is what it means, what usually causes it, and the safest order to work through fixes on Windows 11 and Windows 10.

In short

Windows detected corruption in a critical kernel data structure and stopped.

What KERNEL_SECURITY_CHECK_FAILURE means

The kernel runs integrity checks on important data structures. This stop means one of those checks failed. Faulty drivers, incompatible software, memory or disk errors and damaged system files can all corrupt kernel data.

Common causes

Outdated or incompatible drivers
Memory errors
Damaged system files or drive errors
Incompatible third-party security or system tools

How to fix KERNEL_SECURITY_CHECK_FAILURE

Work through these in order and test after each one. Stopping as soon as the crashes stop tells you which change mattered.

Undo the most recent change. If the blue screens began after a Windows update, a new driver or new software, remove that change first. Uninstall the update from Settings, Windows Update, Update history, or roll a driver back in Device Manager (right-click the device, Properties, Driver, Roll Back Driver).
Repair Windows system files. Open Terminal (Admin) and run sfc /scannow. If it reports damage it could not repair, run DISM /Online /Cleanup-Image /RestoreHealth, restart, and run sfc /scannow once more.
Test the memory. Run Windows Memory Diagnostic (search for it in Start) for a quick check, then MemTest86 for several passes if the crashes continue. Any error points to a faulty stick or slot, or to memory settings the hardware cannot run reliably.
Check the health of the drive. Read the SMART data with the drive maker's tool or CrystalDiskInfo and look for reallocated or pending sectors, media errors and a low remaining-life figure. Back up important files first if the drive reports any warning.
Return the PC to stock settings. Reset the BIOS to defaults, then leave XMP or EXPO, CPU or GPU overclocks and undervolts (including per-core offsets such as Curve Optimizer) switched off while you test. If the crashes stop, re-enable one setting at a time to find the unstable one.

When to stop and protect your data

Repeated occurrences with clean memory and drive tests justify a clean Windows installation to rule out deep software corruption.

Not sure this is your code?

The stop code appears as text on the blue screen. If the PC restarted before you could read it, open Event Viewer, then Windows Logs, then System, and look for a BugCheck event with ID 1001. You can also search all stop codes.

Related guides

Other system file and kernel errors

CRITICAL_PROCESS_DIED (0xEF)

Frequently asked questions

What does KERNEL_SECURITY_CHECK_FAILURE mean?

Windows detected corruption in a critical kernel data structure and stopped. The kernel runs integrity checks on important data structures. This stop means one of those checks failed. Faulty drivers, incompatible software, memory or disk errors and damaged system files can all corrupt kernel data.

What usually causes KERNEL_SECURITY_CHECK_FAILURE?

Typical causes: Outdated or incompatible drivers; Memory errors; Damaged system files or drive errors; Incompatible third-party security or system tools.

How do I fix KERNEL_SECURITY_CHECK_FAILURE (0x00000139)?

A sensible order is: 1) Undo the most recent change; 2) Repair Windows system files; 3) Test the memory; 4) Check the health of the drive. Repeated occurrences with clean memory and drive tests justify a clean Windows installation to rule out deep software corruption.

Use this guidance carefully

A stop code can have several causes, and these steps are general guidance rather than a diagnosis of your PC. If your data matters, back it up before repairs. If the problem continues, a hardware technician can test the parts.

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