Windows BSOD Error 0x00000149 — What It Means & How to Fix It

What Does This Error Mean?

Windows BSOD 0x00000149 (KERNEL_STACK_LOCKOUT_ORDER_VIOLATION) means a kernel component acquired locks in the wrong order, which can cause a deadlock. A deadlock is when two parts of the system each wait for the other to finish — and neither can proceed. Windows detects this and crashes to prevent the system from completely freezing. This is typically caused by a buggy driver or, less commonly, a hardware problem.

Affected Models

Windows 10
Windows 11

Common Causes

A device driver acquired kernel locks in the wrong order, violating Windows synchronization rules
A recently updated or installed driver has a threading or synchronization bug
A third-party security, filter, or storage driver is conflicting with Windows kernel operations
Faulty RAM is causing memory corruption in the kernel's lock management structures
An overclocked CPU or RAM is producing instability in kernel operations

How to Fix It

Check what was installed or updated before the crashes started. Go to Control Panel > Programs > Programs and Features and sort by install date. Also check Settings > Windows Update > View Update History. Roll back or uninstall any recent changes.

Identifying the trigger is the most important first step. If crashes started after a specific install or update, removing it will almost certainly stop the BSODs.
Run Windows Memory Diagnostic to rule out RAM as a cause. Press the Windows key, search for 'Windows Memory Diagnostic', and select 'Restart now and check for problems.' Check the results after reboot.

RAM faults cause many different types of BSODs, including kernel lock errors. Testing memory first rules out the most common hardware cause.
Update all device drivers. Right-click Start > Device Manager. Look for any warning icons. Update chipset, GPU, network, USB, and storage drivers from the hardware manufacturers' websites.

Driver bugs are the primary software cause of kernel lock order violations. Manufacturer-released driver updates often contain specific fixes for these issues.
Analyze the crash dumps using WhoCrashed. Download WhoCrashed for free from resplendence.com. Run it and point it to C:\Windows\Minidump. It will read the crash reports and identify the driver (.sys file) responsible.

Once you know the driver name, you can search for it online to determine which program or hardware it is associated with, then update or remove it.
If you have overclocking active, disable it. Restart your PC and enter the BIOS by pressing the key shown on your manufacturer's logo screen (usually Del, F2, or F10). Find overclocking or XMP/EXPO settings and set everything to default/stock speeds.

Overclocking pushes hardware beyond rated specifications. Even small overclocks on RAM can cause kernel-level instability that produces this type of BSOD.

When to Call a Professional

This is a low-level BSOD that is difficult to diagnose without technical tools like WinDbg. If you cannot resolve it by updating drivers or testing hardware, bring the PC to a technician. For systems under warranty, contact the manufacturer — hardware defects can sometimes cause this error.

Frequently Asked Questions

What is a kernel lock and why does getting the order wrong cause a crash?

A kernel lock is like a 'do not disturb' sign that Windows puts on a resource while it is being used. Drivers and system code must acquire these locks in the correct order — otherwise two pieces of code can get stuck waiting for each other forever. This is called a deadlock. Windows detects this situation and crashes intentionally — because a deadlock means the system can never recover on its own.

Could this be a virus?

In rare cases, rootkits and very sophisticated malware operate at the kernel level and could cause this type of error. Run a full scan with Windows Defender and also try Malwarebytes (free version) to check. However, a driver bug or hardware issue is far more likely. If malware scans come back clean, focus on driver and hardware troubleshooting.

How do I enter the BIOS to disable overclocking?

Restart your PC and watch for a prompt on the startup screen that says which key to press — usually Delete, F2, F10, or F12. Press that key repeatedly right after turning on the PC. Once in the BIOS, look for sections labeled 'Overclocking', 'Performance', or 'XMP/EXPO'. Set the CPU and RAM speeds to their default values. Save and exit. The PC will restart at stock speeds.