The IRQL_NOT_LESS_OR_EQUAL blue screen error appears when a driver or piece of software tries to access a memory address it is not allowed to access at the current Interrupt Request Level. Windows cannot continue safely and crashes to prevent data corruption. The error almost always points to a driver problem, a RAM issue, or software incompatibility.
This guide works through every fix in order from most likely to least: checking for driver conflicts first, then running Windows Memory Diagnostic, and finally performing a System Restore if the error started after a specific change to your system.
Quick Answer
Open Device Manager (Win + X, then Device Manager), look for any device with a yellow exclamation mark, right-click it, and choose Update driver. If no flagged devices appear, check for recently installed drivers and roll them back under Properties > Driver > Roll Back Driver. If the BSOD started after a Windows Update or software installation, run a System Restore to a point before the change.
Check for Driver Conflicts
Incompatible or corrupted drivers are the most common cause of IRQL_NOT_LESS_OR_EQUAL. Device Manager flags problematic drivers with a yellow warning icon, which makes them easy to spot.
- Press Win + X and click Device Manager.
- Expand every category and look for any device with a yellow exclamation mark.
- Right-click any flagged device and select Update driver. Choose Search automatically for drivers.
- Restart your computer and check if the BSOD recurs.
If Device Manager shows no flagged devices but the BSOD started after a driver update, open the device’s Properties, go to the Driver tab, and click Roll Back Driver to restore the previous version. GPU drivers are a common culprit, so check your graphics card driver specifically if the error appears during gaming or video playback.
Update Drivers via Windows Update
Windows Update sometimes delivers driver updates that Device Manager’s automatic search misses. After checking Device Manager, open Settings > Update and Security > Windows Update and click View optional updates. Any pending driver updates appear there. Install them, restart, and check whether the BSOD is gone.
For graphics and network adapters specifically, also check the manufacturer website directly. NVIDIA, AMD, Intel, and Realtek all publish drivers that may be several versions ahead of what Windows Update provides. Download and install the latest version, restart, and monitor the system.
Perform a Clean Boot
If the BSOD happens during startup or shortly after logging in, a third-party service or startup program may be the cause rather than a driver. A clean boot starts Windows with only essential Microsoft services, isolating the problem.
- Press Win + R, type msconfig, and press Enter.
- On the Services tab, check Hide all Microsoft services, then click Disable all.
- Click the Startup tab and then Open Task Manager. Disable all startup items.
- Close Task Manager, click OK in System Configuration, then restart your PC.
If Windows boots without a BSOD in clean boot mode, a non-Microsoft service is responsible. Re-enable services in groups of four or five, restarting between each group, until the BSOD reappears. The last group you enabled contains the problematic service. Narrow it down by enabling them one at a time from that group.
Run Windows Memory Diagnostic
Faulty RAM causes IRQL_NOT_LESS_OR_EQUAL BSODs because bad memory can make drivers appear to access invalid addresses even when the driver itself is fine. If you have ruled out drivers and software, testing your RAM is the next step.
- Type Windows Memory Diagnostic in the Start menu and open it.
- Select Restart now and check for problems. Save any open work first.
- Windows restarts and runs the memory test automatically. Results appear after Windows boots back up, or you can view them in Event Viewer under Windows Logs > System (look for source “MemoryDiagnostics-Results”).
If errors are found, the next step is to isolate which RAM stick is faulty. If you have multiple sticks, shut down the PC, remove all but one stick, and test each one individually by running Windows Memory Diagnostic with only that stick installed. Replace any stick that produces errors. Even a single bad memory cell can cause persistent BSODs.
Perform System Restore
If IRQL_NOT_LESS_OR_EQUAL started after a Windows Update, a driver change, or a software installation, System Restore can roll your system back to the state it was in before the change without affecting your personal files.
- Type System Restore in the Start menu and open Create a restore point.
- Click System Restore on the System Protection tab.
- Click Next and choose a restore point from before the BSOD started appearing.
- Follow the prompts and let Windows restore. The PC will restart once during the process.
System Restore does not delete personal files. It reverts installed programs, drivers, and system settings to the state they were in at the selected restore point. If the BSOD was caused by a recent software or driver change, this is one of the most reliable fixes available. Pairing this fix with a disk health check afterward is a good idea to rule out hardware as a contributing factor.