How to Fix BSOD DRIVER_IRQL_NOT_LESS_OR_EQUAL (0x000000D1)
What error 0x000000D1 means
Windows organizes running code by privilege level. Drivers that talk directly to hardware run at an elevated interrupt level (IRQL), and at that level only certain memory is fair game. When a driver reaches for memory it isn't allowed to touch — pageable memory at an IRQL that was too high, or an address that doesn't belong to it — Windows stops everything with the DRIVER_IRQL_NOT_LESS_OR_EQUAL blue screen (stop code 0x000000D1) rather than let the corruption spread. The name is technical, but the translation is simple: a driver broke the rules.
The good news is that this blue screen is unusually helpful. It usually prints the offending driver's filename right on the crash screen — ndis.sys, netio.sys, or your Wi-Fi card maker's driver are the classic ones — so you start with a named suspect instead of guessing. Wi-Fi and network drivers are the top offenders because they move data at high IRQL all day long. Antivirus, firewall, and VPN software install their own network-hooking drivers, which is why they come in second. Sometimes the driver was fine until a Windows update replaced it with an incompatible version, which is why the crash's start date matters: match it to the last update or driver install, and you often have your answer before opening Device Manager.
Common causes
- Faulty Wi-Fi or network driver: the driver for your Wi-Fi card or Ethernet adapter mishandles memory at high IRQL — the most common trigger by far.
- Antivirus or VPN drivers: third-party security and VPN tools install network-hooking drivers that can break the same memory rules.
- Driver broken by a Windows update: an update installed an incompatible driver version, or changed something the old driver relied on.
- Corrupted Windows system files: damaged built-in drivers and components (like ndis.sys itself) can trigger the crash even with good hardware.
- Faulty RAM: rare for this code, but a bad memory stick can corrupt the regions drivers use and mimic a driver bug.
How to fix error 0x000000D1 — step by step
Work through these fixes in order. Step 1 is the most important: knowing the driver's filename turns the rest into a targeted repair instead of guesswork.
- Identify the crashing driver from the minidump. The blue screen usually names the offending driver at the bottom, such as
ndis.sys,netio.sys, or a Wi-Fi driver's .sys file. For the full detail, openC:\Windows\Minidumpin File Explorer and note the newest .dmp file. The free portable tool BlueScreenView reads that file in plain English and highlights the driver in red. Write down the exact .sys filename — everything that follows targets that driver, and this one step turns a mystery crash into a named suspect. - Update or roll back that driver. Press Win + X and open Device Manager, then find the device the driver belongs to — network or Wi-Fi adapters for
ndis.sysandnetio.sys, for example. If the crashes started right after a driver update, right-click the device, open Properties, go to the Driver tab, and click Roll Back Driver. Otherwise click Update driver > Search automatically for drivers, and if Windows finds nothing new, download the latest driver from the motherboard, laptop, or Wi-Fi card maker's support page. Manufacturer drivers beat Windows Update's generic ones for this blue screen. - Uninstall the most recent Windows update. Sometimes the driver is fine and the update broke it. Open Settings > Windows Update > Update history > Uninstall updates. Find the most recent update — especially a driver or cumulative update installed just before the crashes began — select it, and click Uninstall. Restart and use the PC normally for a day. If the blue screens stop, pause Windows Update for a couple of weeks before letting it reinstall the same update, and check the driver maker's site for a compatible version in the meantime.
- Repair system files with SFC and DISM. Corrupted system files can corrupt the drivers that ship with Windows. Open an admin Terminal (right-click Start > Terminal (Admin)). First run
sfc /scannowand let it finish — it repairs protected Windows files. Then runDISM /Online /Cleanup-Image /RestoreHealth, which repairs the component store that SFC relies on. If SFC reported corruption it could not fix, run it once more after DISM completes. Restart the PC and see whether the crashes stop. - Temporarily disable third-party antivirus or VPN software. Antivirus, firewall, and VPN tools install their own network drivers that hook deep into Windows, and they are a classic cause of this exact blue screen. Temporarily disable the third-party antivirus (Settings > Apps > Installed apps, or use the vendor's own disable option) and disconnect or uninstall any VPN. Run the PC for a day with only Windows Defender active. If the crashes stop, the security software's driver was the culprit — check the vendor's support page for an updated version before reinstalling it.
- Reset the network stack. When the suspect is a network-class driver such as
ndis.sysornetio.sys, corrupted network configuration can keep triggering the crash. Open an admin Terminal and runnetsh winsock reset, thennetsh int ip reset, thenipconfig /flushdns. Restart the PC. These commands rebuild the Winsock catalog and the TCP/IP stack to a clean default without touching your personal files. Reconnect to your Wi-Fi or Ethernet after the restart and confirm the connection works. - Test the RAM to rule out hardware. A driver bug is the cause of 0x000000D1 in the vast majority of cases, but faulty RAM can corrupt the same memory regions and produce an identical-looking blue screen. Press Win + R, type
mdsched.exe, and choose "Restart now and check for problems." If the test reports any error, a memory stick is defective and needs replacing — no driver fix will help while the hardware is corrupting memory. If it passes clean, you can be confident the problem is software and the steps above cover it.
Did this fix it? Quick checklist
- The offending .sys driver is identified from the blue screen or crash dump
- That driver has been updated, rolled back, or replaced with the manufacturer's version
- SFC and DISM both completed without unrepairable corruption
- Third-party antivirus/VPN ruled out as the trigger
If crashes continue after all seven steps, boot into Safe Mode (interrupt boot three times, then Troubleshoot > Advanced options > Startup Settings > Restart, press 4) and remove the suspect driver completely from Device Manager with "Delete the driver software" checked, then install the clean manufacturer driver in normal mode. As a last resort, a clean Windows install replaces every driver and system file — but run the memory test first, since no reinstall can fix genuinely faulty RAM.
Frequently asked questions
What does DRIVER_IRQL_NOT_LESS_OR_EQUAL (0x000000D1) mean?
It means a driver tried to access pageable memory at an interrupt level (IRQL) that was too high, or touched memory it was never allowed to touch. In plain terms, a driver broke the memory rules Windows enforces. The crash dump usually names the offending driver file, which is why this blue screen is one of the more diagnosable ones.
Which driver usually causes 0x000000D1?
The most common offenders are network and Wi-Fi drivers — files like ndis.sys, netio.sys, and the Wi-Fi card maker's own .sys driver — followed by antivirus and VPN drivers that hook into the network stack. Graphics and storage drivers cause it less often. The blue screen itself usually prints the driver's filename at the bottom, which tells you exactly where to look.
Can a recent Windows update cause 0x000000D1?
Yes. A Windows update can install a newer driver that is incompatible with your hardware, or break an existing driver. If the crashes started right after Patch Tuesday or a cumulative update, uninstalling the most recent update and rolling back the driver are the fastest fixes. Pausing updates briefly while the driver maker releases a compatible version prevents it from coming right back.
Will reinstalling Windows fix 0x000000D1?
Usually, but only if the cause is software — which it almost always is with this code. A clean install replaces every driver and system file, so a driver bug is gone. It will not fix genuinely faulty RAM, so run the memory diagnostic first. A clean install is a last resort: try identifying and replacing the bad driver first, since that fixes the root cause without wiping your setup.