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0x000000D1DRIVER_IRQL_NOT_LESS_OR_EQUALStop codeWidely reported

DRIVER_IRQL_NOT_LESS_OR_EQUAL (0xD1): what it means and how to fix it

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

Quick answer

This error occurs when a system driver tries to access memory it is not allowed to use while the processor is busy with high-priority tasks. It is most often caused by outdated or corrupted hardware drivers. Start by checking your system logs to identify the specific driver responsible for the crash.

What it means

Understanding the Error

When you see the DRIVER_IRQL_NOT_LESS_OR_EQUAL error, Windows is reporting that a piece of software, known as a driver, attempted to read or write to a memory address that was either protected or unavailable at that specific moment. In technical terms, the driver was operating at an interrupt request level (IRQL) that was too high to perform the memory operation it requested.

Why It Happens

Drivers act as translators between your hardware and the Windows operating system. For the system to remain stable, drivers must follow strict rules regarding how they handle memory. When a driver ignores these rules—for example, by trying to access data that the system has temporarily moved to the hard drive (paged memory) while the processor is in a high-priority state—Windows triggers this stop code to prevent data corruption or further system instability. This is essentially the operating system's way of forcing a shutdown to protect your files and hardware from a malfunctioning driver.

Common causes

  • A faulty or outdated hardware driver is installed on the system.
  • A driver is attempting to access an invalid memory address.
  • Recently installed hardware is incompatible with your current version of Windows.
  • System files are corrupted due to a failed update or disk error.
  • A driver was improperly unloaded while still in use by the system.

How to fix it

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

  1. Update your hardware drivers

    Use this if the error happens frequently and you suspect a specific device driver is outdated.

    1. Right-click the Start button and select Device Manager.
    2. Locate the device category that might be causing issues, such as Display adapters or Network adapters.
    3. Right-click the specific device and select Update driver.
    4. Choose Search automatically for drivers to let Windows find the latest version.
    Did this fix it?

  2. Check the Event Viewer for clues

    Use this to identify which specific driver or file name is triggering the crash.

    1. Type Event Viewer into the search bar and open the application.
    2. Expand Windows Logs in the left sidebar and select System.
    3. Look for Error entries that coincide with the time of your crash.
    4. Check the General tab in the bottom pane for a file name ending in .sys, which often points to the culprit.
    Did this fix it?

  3. Run the Windows Update troubleshooter

    Use this if you suspect the issue is related to a recent system update or general driver compatibility.

    1. Open Settings by pressing Windows Key + I.
    2. Navigate to System and then Troubleshoot.
    3. Select Other troubleshooters.
    4. Find Windows Update and click the Run button.
    Did this fix it?

  4. Remove recently installed hardware

    Use this if the blue screen started appearing immediately after you connected a new device.

    1. Shut down your computer completely.
    2. Disconnect the recently added hardware device.
    3. Restart your computer to see if the error persists.
    4. If the system stabilizes, check the manufacturer website for newer, compatible drivers for that device.
    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

Is my hardware broken when I see this error?

Not necessarily. While it can indicate failing hardware, it is much more frequently caused by a software driver that is not communicating correctly with your hardware.

Can I fix this by reinstalling Windows?

Reinstalling Windows is a last resort. Most of the time, updating or removing the specific problematic driver will resolve the issue without needing a full system wipe.

What does the .sys file name in the error mean?

The .sys file mentioned in a blue screen error is the specific driver file that was running when the crash occurred, helping you identify which component is responsible.

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