How to Fix IRQL_NOT_LESS_OR_EQUAL in Windows 11

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Ankit Kumar
Windows 11BSODTroubleshootingFixDrivers

The Problem

Windows stops with IRQL_NOT_LESS_OR_EQUAL (technical code 0x0000000A, sometimes 0xD1). A kernel-mode driver touched memory at the wrong priority level. In plain terms: a driver misbehaved, or the memory it read was corrupt.

Network adapters, graphics drivers, and audio drivers cause most of these. Bad RAM and unstable memory overclocks cause the rest.

Wrong stop code? The general blue screen guide lists them all. PC reboots before the desktop loads? Get into Safe Mode first so you can work.

Symptoms

  • Blue screen reading IRQL_NOT_LESS_OR_EQUAL, often with DRIVER_IRQL_NOT_LESS_OR_EQUAL and a .sys filename.
  • Crashes when connecting to Wi-Fi, starting a game, or plugging in a USB device.
  • Began immediately after new hardware, a driver update, or enabling XMP/EXPO.

Step 1: Read the Driver Name

  1. Photograph the blue screen — the line under the stop code names the driver.
  2. Or check Event Viewer → Windows Logs → System → the BugCheck entry.
  3. Common names: Netwtw*.sys (Intel Wi-Fi), rt640x64.sys (Realtek Ethernet), nvlddmkm.sys (NVIDIA), atikmdag.sys (AMD), RTKVHD64.sys (Realtek audio), iaStorAC.sys (Intel storage).

Step 2: Fix the Named Driver First

  1. Right-click Start → Device Manager and locate that device.
  2. Properties → Driver tab → Roll Back Driver if the crashes are new.
  3. Otherwise Uninstall device (tick Attempt to remove the driver), restart, then install the current driver from the hardware maker's own site.
  4. Network adapters are the most frequent culprit — grab the driver from Intel, Realtek, or your laptop maker rather than Windows Update.
  5. Step-by-step: how to update outdated drivers.

Step 3: Disable Memory Overclocking

Unstable RAM timings produce this stop code at random intervals.

  1. Restart into BIOS/UEFI (usually Del, F2, or F10 at the logo).
  2. Load Optimized Defaults, which clears XMP/EXPO profiles.
  3. Save and exit. Run the PC at stock speed for a day.
  4. If it is stable, your memory profile was too aggressive — use a slower profile or update the BIOS, which frequently ships memory-compatibility fixes.

Step 4: Test Your RAM

  1. Press Win + R, type mdsched.exe, press Enter.
  2. Choose Restart now and check for problems and let both passes complete.
  3. Any reported error means a failing stick. With multiple sticks, test one at a time in the same slot.
  4. For a stricter test, run MemTest86 from USB. More on memory faults: MEMORY_MANAGEMENT blue screen.

Step 5: Repair System Files

  1. Right-click Start → Terminal (Admin).
  2. Run: 
    sfc /scannow
  3. Then: 
    DISM /Online /Cleanup-Image /RestoreHealth
  4. Restart. Details: repair Windows 11 with SFC and DISM.

Step 6: Disconnect Recently Added Hardware

  1. Unplug USB hubs, docks, capture cards, external drives, and controllers.
  2. Restart and use the PC normally for a few hours.
  3. Reconnect one device at a time. The crash returns with the faulty one.
  4. If a USB device is involved, also read fix USB device not recognized.

Step 7: Remove Third-Party Antivirus

  1. Uninstall the suite with the vendor's own removal tool.
  2. Restart and run on Microsoft Defender for a day.
  3. If crashes stop, the suite's kernel driver was at fault.

Step 8: Identify the Driver with Driver Verifier

Use this only when Steps 1-7 leave you with no name.

  1. Create a restore point first: create a system restore point.
  2. In an admin Terminal, run verifier, choose Create custom settings → Select individual settings from a full list, and enable Special Pool, Force IRQL checking, and Pool Tracking.
  3. Select Select driver names from a list and tick only non-Microsoft drivers.
  4. Restart. The next crash names the guilty driver.
  5. Switch it off afterwards: verifier /reset, then restart. If Windows will not boot, do this from Safe Mode.

What Not to Do

  • Don't install a "driver booster" app. Mismatched drivers are the number-one cause of this exact stop code.
  • Don't leave Driver Verifier enabled once you have your answer.
  • Don't assume it's RAM until the named driver has been ruled out.

Still Not Working?

If Verifier finds nothing, memory tests pass, and stock BIOS settings do not help, suspect the motherboard or PSU — especially if the stop codes vary between crashes. Back up your files, then try reinstalling Windows without losing data.

Related stop codes: SYSTEM_SERVICE_EXCEPTION, DRIVER_POWER_STATE_FAILURE, and DPC_WATCHDOG_VIOLATION.

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