How to Fix IRQL_NOT_LESS_OR_EQUAL Error on Windows 11

11 Nisan 2026 admin 1 Görüntüleme 0 Comments BSOD, device drivers, IRQL_NOT_LESS_OR_EQUAL error, memory diagnostics, system restore, windows 11

The IRQL_NOT_LESS_OR_EQUAL error is a common Blue Screen of Death (BSOD) on Windows 11 that often points to driver, memory, or hardware conflicts. This guide walks you through practical, step-by-step solutions to identify the root cause and fix the error safely.

What is the IRQL_NOT_LESS_OR_EQUAL error?

The IRQL_NOT_LESS_OR_EQUAL error occurs when a driver or kernel-mode process attempts to access a memory address at an Interrupt Request Level (IRQL) that is too high or invalid. In plain terms, a component tried to use memory it shouldn’t, and Windows stopped to prevent system corruption. Common triggers include faulty drivers, bad RAM, incompatible software, or problematic hardware.

Tip: Note down any error filenames displayed on the BSOD (for example, a .sys file). They often identify the problematic driver.

Troubleshooting checklist

Work through these steps from least to most invasive. Back up important files before making major changes like system restores or hardware swaps.

Boot into Safe Mode when possible to prevent automatic drivers or services from loading.
Update Windows and device drivers.
Run memory and disk diagnostics.
Uninstall recently installed software or updates.
Perform a clean boot to isolate services.

Step 1 — Boot into Safe Mode (if the PC won’t start normally)

Safe Mode loads a minimal set of drivers and services. If the error stops in Safe Mode, it’s likely caused by a driver or third-party software.

Hold Shift and select Restart from the Power menu, then navigate to Troubleshoot > Advanced options > Startup Settings > Restart. Choose Enable Safe Mode (option 4) or Safe Mode with Networking (option 5).

Step 2 — Update Windows and drivers

Outdated or corrupt drivers are a primary cause of the IRQL_NOT_LESS_OR_EQUAL error. Update Windows first, then update drivers for network adapters, graphics cards, and motherboard/chipset.

Open Settings > Windows Update, and install all available updates.
Use Device Manager: right-click Start > Device Manager. Expand each category, right-click devices, and choose Update driver. Preferably get drivers from the manufacturer website.

Good practice: Download network and storage drivers from your PC or motherboard manufacturer’s support page for the latest stable versions.

Step 3 — Check memory (RAM)

Faulty RAM often produces this error. Run Windows Memory Diagnostic or MemTest86 to find issues.

Windows Memory Diagnostic: Press Windows key, type “Windows Memory Diagnostic”, run it, and choose Restart now and check for problems.
For deeper tests, use MemTest86 (bootable). Let it run several passes; any errors indicate defective RAM modules.
If you have multiple RAM sticks, test them one at a time to isolate a bad module.

Step 4 — Check storage and system files

Corrupt system files or disk errors can trigger crashes. Run built-in checks to verify integrity.

Run CHKDSK: Open Command Prompt as admin and run chkdsk /f /r for the system drive. You may need to schedule on next reboot.
System File Checker: In an elevated Command Prompt, run sfc /scannow to repair corrupted system files.
DISM: If SFC reports issues, run DISM /Online /Cleanup-Image /RestoreHealth, then rerun sfc /scannow.

Step 5 — Perform a clean boot to isolate software conflicts

A clean boot disables third-party services and startup items so you can find the culprit without full Safe Mode restrictions.

Press Windows key + R, type msconfig, and press Enter. On the Services tab, check Hide all Microsoft services and click Disable all. On Startup, open Task Manager and disable nonessential startup items. Restart and test.
If the error stops, re-enable services/startup items in small groups to find the responsible component.

Important: When enabling services again, reboot between groups to see when the error returns. This narrows down the cause faster.

Step 6 — Roll back or uninstall problematic drivers and updates

If a specific driver or Windows update coincided with the error, roll back or uninstall it.

Device Manager > right-click the device > Properties > Driver tab > Roll Back Driver (if available).
Settings > Windows Update > Update history > Uninstall updates to remove recent updates that may be causing issues.

Step 7 — Restore or reset Windows

If earlier steps don’t help, consider System Restore or repairing Windows.

System Restore: Use a restore point from before the error started (Control Panel > Recovery > Open System Restore).
Reset this PC: Settings > System > Recovery > Reset this PC. Choose Keep my files or Remove everything. This reinstalls Windows while optionally preserving personal data.

Hardware checks and advanced options

If software troubleshooting fails, look at hardware components:

Reseat RAM and check motherboard slots.
Check CPU heatsink and temperatures; overheating can cause instability.
Test with another known-good power supply; voltage issues can create random BSODs.
If you recently added new hardware, disconnect it and test stability.

Issue	Quick Test	Expected Fix
Driver conflict	Boot Safe Mode; check Device Manager	Update/rollback driver or uninstall software
Bad RAM	Run MemTest86 or Windows Memory Diagnostic	Replace faulty RAM stick(s)
Corrupted system files	Run SFC and DISM	Repair or reset Windows

Warning: Avoid downloading drivers from unverified third-party sites. Always prefer manufacturer or Microsoft sources to reduce malware and instability risk.

FAQ

Q: Can faulty RAM cause the IRQL_NOT_LESS_OR_EQUAL error?

A: Yes. Bad RAM is a common cause. Running memory diagnostics and testing modules individually helps isolate and confirm faulty sticks.

Q: Is this error always hardware-related?

A: No. It can be caused by software issues such as corrupt drivers or incompatible applications, as well as hardware problems like bad RAM or failing storage.

Q: Will resetting Windows fix the error?

A: Resetting Windows can resolve the issue when it stems from deep system corruption or persistent driver conflicts. Always back up data first.

Q: How do I find which driver caused the crash?

A: Check the BSOD screen for filenames (often ending in .sys). Use Event Viewer and dump files (minidumps) located in C:WindowsMinidump. Tools like BlueScreenView or WinDbg can parse dump files to point to suspect drivers.

Conclusion

Resolving the IRQL_NOT_LESS_OR_EQUAL error on Windows 11 usually requires systematic troubleshooting: update drivers, test memory and storage, use Safe Mode and clean boot procedures, and, if needed, restore or reset Windows. Start with non-destructive checks and progress to hardware tests if software fixes fail. With patience and the steps above, you can identify the cause and restore system stability.

Final tip: Keep regular backups and create system restore points before installing major updates or new drivers to simplify recovery if the error returns.