Drivers · critical

How to fixDRIVER-IRQL-MISMATCH

Driver IRQL mismatch (IRQL_NOT_LESS_OR_EQUAL variant)

What this error means

Driver IRQL mismatch (IRQL_NOT_LESS_OR_EQUAL variant) ranks as a critical-severity system driver issue in our database. A driver attempted to access memory at an incorrect IRQL level. Unlike standard IRQL_NOT_LESS_OR_EQUAL, this variant specifically indicates the driver is operating at a higher IRQL than allowed for the memory access type. Common in drivers that use spinlocks incorrectly or perform I/O at elevated interrupt levels, bypassing Windows kernel safety checks. The steps below are ordered to resolve this efficiently.

Before you begin

Save open work and back up important files. Use instructions for your exact device and software version. If Windows cannot start, see the startup guide.

Work through these checks

0 of 3 complete
01Identify faulting driver from minidump via WinDbg
  1. Identify faulting driver from minidump via WinDbg
What to expect

Check whether the original symptom still occurs.

If it does not help

Continue only if this check applies to your device. Consult its manufacturer if you are unsure.

Browse related errors
02Update all hardware drivers to latest versions
  1. Update all hardware drivers to latest versions
What to expect

Check whether the original symptom still occurs.

If it does not help

Continue only if this check applies to your device. Consult its manufacturer if you are unsure.

Browse related errors
03Uninstall recently installed hardware or software drivers
  1. Uninstall recently installed hardware or software drivers
What to expect

Check whether the original symptom still occurs.

If it does not help

Continue only if this check applies to your device. Consult its manufacturer if you are unsure.

Browse related errors

Possible causes

  • Third-party driver with IRQL handling bug
  • Outdated hardware driver using deprecated kernel APIs
  • Driver verifier catching existing latent bugs