What DRIVER_IRQL_NOT_LESS_OR_EQUAL means

This is the driver-specific cousin of IRQL_NOT_LESS_OR_EQUAL. A driver touched pageable memory while the processor was at a priority level that forbids it. The blue screen often names the driver file, and that driver (or something it works with) is the first place to look.

Common causes

  • A faulty network adapter, Wi-Fi or Bluetooth driver
  • Security software, VPN or virtualization drivers
  • Outdated chipset or storage drivers
  • Failing RAM, less often

How to fix DRIVER_IRQL_NOT_LESS_OR_EQUAL

Work through these in order and test after each one. Stopping as soon as the crashes stop tells you which change mattered.

  1. Note the file name on the blue screen. If the screen shows a line such as "What failed" followed by a .sys file, write it down. Searching that file name shows which driver it belongs to, which tells you what to update or remove. The named file is the code that crashed, which is not always the root cause.
  2. Update or reinstall the driver that was named. Get the driver from the device or motherboard maker rather than relying on Windows Update alone. For a network adapter, download the package on another PC if the affected PC cannot stay online long enough.
  3. Temporarily remove VPN and security add-ons. Uninstall third-party VPN clients, firewall add-ons and similar low-level software, then check whether the crashes stop. Reinstall the current version afterwards if it was not the cause.
  4. Test the memory. Run Windows Memory Diagnostic (search for it in Start) for a quick check, then MemTest86 for several passes if the crashes continue. Any error points to a faulty stick or slot, or to memory settings the hardware cannot run reliably.
  5. Repair Windows system files. Open Terminal (Admin) and run sfc /scannow. If it reports damage it could not repair, run DISM /Online /Cleanup-Image /RestoreHealth, restart, and run sfc /scannow once more.
When to stop and protect your data

If no driver name is shown and the crashes happen at random, treat it like a memory or hardware problem and test RAM before changing more software.

Not sure this is your code?

The stop code appears as text on the blue screen. If the PC restarted before you could read it, open Event Viewer, then Windows Logs, then System, and look for a BugCheck event with ID 1001. You can also search all stop codes.

Related guides

Other driver errors