Skip to content
PCDecoder
0x0000001EKMODE_EXCEPTION_NOT_HANDLEDStop codeWidely reported

KMODE_EXCEPTION_NOT_HANDLED (0x1E): what it means and how to fix it

Updated Oct 3, 2026 · Checked against Microsoft documentation · How this page is made

Quick answer

Bug check 0x1E indicates that a program running inside the Windows kernel encountered an error condition that was not caught by an error handler. A faulty device driver, memory conflict, or BIOS incompatibility is usually responsible. If a specific driver file is shown on your crash screen, start by disabling or updating that driver.

What it means

Windows divides system tasks between user mode, where regular desktop applications run, and kernel mode, where the operating system core and hardware drivers operate. Software running in kernel mode has direct access to system memory and hardware resources. When a kernel-mode program encounters an irregular situation—such as an invalid memory request or an unexpected breakpoint—it raises an exception. If the software lacks a designated routine to intercept and resolve that exception, Windows halts the system to prevent operating system corruption.

The crash details include four diagnostic parameters. The first parameter specifies the exception code that went unhandled. A frequent code is 0xC0000005 (STATUS_ACCESS_VIOLATION), which indicates that a driver attempted to access an invalid or restricted memory address. Another code is 0x80000002 (STATUS_DATATYPE_MISALIGNMENT), occurring when an unaligned data reference is made. Exception code 0x80000003 (STATUS_BREAKPOINT) indicates that a hard-coded breakpoint or assertion was triggered while no kernel debugger was attached.

The second parameter is the memory address where the failure happened. When Windows can trace this address to an active component, it displays the specific driver name on the screen.

Why it happens

Faulty device drivers and system services cause most occurrences of this stop code. Because drivers operate with kernel privileges, an unhandled programming exception within a driver crashes the entire operating system rather than just closing a single window.

Hardware issues can also trigger bug check 0x1E. Faulty physical RAM modules, IRQ conflicts, and memory mapping conflicts can corrupt kernel operations. An outdated or incompatible system BIOS can also fail to properly manage hardware handoffs to Windows, particularly during the startup sequence or immediately following Windows Setup.

Common causes

  • A faulty device driver or system service triggered an unhandled exception, such as an access violation (0xC0000005).
  • An outdated system BIOS caused an incompatibility with Windows during startup or after setup.
  • Physical memory conflicts, IRQ conflicts, or failing RAM modules caused memory corruption.
  • Newly installed hardware is incompatible with the installed version of Windows.
  • A kernel thread triggered a breakpoint or assertion (0x80000003) without a kernel debugger attached.

How to fix it

Safest and most likely fixes first. Readers' answers to "Did this fix it?" reorder this list over time.

  1. Disable or roll back the driver in Safe Mode

    Use this if the crash screen identifies a specific driver file or if the system crashes repeatedly during normal startup.

    1. Boot Windows into Safe Mode to access the desktop without loading third-party drivers.
    2. Right-click the Start button and select Device Manager.
    3. Locate the hardware device associated with the driver name displayed on the crash screen.
    4. Right-click the device and choose Properties.
    5. Select the Driver tab and click Roll Back Driver, or click Disable device if rollback is unavailable.
    6. Restart your computer normally and check the hardware manufacturer's website for an updated driver.
    Did this fix it?

  2. Check the System Log in Event Viewer

    Use this when the blue screen does not display the name of the failing driver.

    1. Right-click the Start button and select Event Viewer.
    2. Expand Windows Logs in the left sidebar and select System.
    3. Search through the log entries recorded at the exact timestamp of the crash.
    4. Review Error entries for references to specific drivers, services, or hardware devices.
    5. Uninstall or update the specific driver or service named in the event details.
    Did this fix it?

  3. Run manufacturer hardware and memory diagnostics

    Use this if the error displays exception code 0xC0000005 or appears intermittently during daily use.

    1. Restart your computer and enter the hardware diagnostic menu using your manufacturer's designated setup key during boot.
    2. Select and run the built-in memory scanner to test physical RAM modules for defects.
    3. Run the full diagnostic suite to identify motherboard, bus, or IRQ conflicts.
    4. Replace any hardware module that fails diagnostic verification.
    Did this fix it?

  4. Update the system BIOS

    Upgrading the BIOS carries risk if power fails during installation, but it resolves errors that occur during Windows Setup or early boot.

    1. Visit your motherboard or computer manufacturer's support page for your exact model.
    2. Check the BIOS release notes to confirm fixes for Windows compatibility or hardware conflicts.
    3. Download the latest BIOS update and read the manufacturer's provided installation instructions.
    4. Apply the BIOS update using the manufacturer's recommended flashing utility.
    5. Restart the computer and observe whether startup completes without the stop code.
    Did this fix it?

  5. Verify hardware compatibility and disconnect recent devices

    Use this if the stop code began appearing immediately after installing new internal or external hardware.

    1. Turn off the computer and disconnect the power source.
    2. Remove the newly installed hardware component or expansion card.
    3. Check the Windows hardware specifications documentation to ensure the component is supported.
    4. Power on the system to confirm whether removing the device resolved the crash.
    Did this fix it?

Is it just you?

25+ Microsoft Q&A threads discuss this. Most recent activity:

Checked Oct 2, 2026. Refreshed automatically every few days.

Sources

Frequently asked questions

What does KMODE_EXCEPTION_NOT_HANDLED mean?

It means a driver or system service running in the Windows kernel generated an error condition that had no error-handling routine to catch it. Windows stops execution to protect files and system integrity.

What is exception code 0xC0000005 in bug check 0x1E?

Exception code 0xC0000005 indicates a memory access violation (STATUS_ACCESS_VIOLATION). A driver attempted to read or write to an invalid or unauthorized memory address.

Can an outdated BIOS cause 0x0000001E?

Yes. A BIOS incompatibility can cause this error, particularly during the startup sequence or after the first restart of Windows Setup.

How do I identify which driver caused error 0x1E?

Check the blue screen text for a driver file name ending in .sys. If none is listed, open Event Viewer and examine the System Log for device or service errors logged at the time of the crash.

More stop codes decoded