Get the fix for the error  IRQL NOT LESS OR EQUAL on Windows XP, Windows Vista, Windows 7, Windows 8 and Windows 10.


The following information on this error has been compiled by NeoSmart Technologies, based on the information gathered and reported by our global network of engineers, developers, and technicians or partner organizations.

Description and Symptoms

The error messages, alerts, warnings, and symptoms below are tied to this error.

Symptom 1: “IRQL NOT LESS OR EQUAL” error screen on startup

The IRQL error is a memory related error that often appears if a system process or a driver attempts to access a memory address without proper access rights.

This, in turn, can be triggered by any of these causes:

  • Corrupt system files
  • Incompatible device drivers
  • Faulty hardware items
  • Incorrect software installation
  • An downgrade to a lower version of Windows, e.g. downgrading Windows 7 to Windows Vista

Here is an example of “IRQL NOT LESS OR EQUAL” error screen:


A problem has been detected and Windows has been shut down to prevent damage 
to your computer.


If this is the first time you've seen this Stop error screen, 
restart your computer. If this screen appears again, follow
these steps:

Check to make sure any new hardware or software is properly installed.
If this is a new installation, ask your hardware or software manufacturer
for any Windows updates you might need.

If problems continue, disable or remove any newly installed hardware 
or software. Disable BIOS memory options such as caching or shadowing.
If you need to use Safe Mode to remove or disable components, restart
your computer, press F8 to select Advanced Startup Options, and then
select Safe Mode.

Technical Information:

*** STOP: 0x00000001 (0x00000001, 0x00000001, 0x00000000, 0x00000000)

Causes of this Error

This error has been known to occur as a result of one of the following causes:

Cause 1: Corrupt system files

The most common cause for this error is a corrupted system file that is required to boot the system. This can happen because of virus attacks, power outages, or disk write errors.

Cause 2: Incompatible device drivers

Another common cause is a newly installed faulty device driver. In that case, reverting to an old version of a driver would be the best solution.

Cause 3: Faulty hardware items

This error can also be caused by a damaged motherboard or a bad RAM module.

Cause 4: Incorrect software installation

Sometimes, a misconfigured Windows service

Cause 5: A downgraded Windows installation

The least common cause for this error is when an older version of Windows is installed on top of a newer one. Sometimes, the system files are not replaced properly, and if that is the case, then the user should back up the files and perform a clean install to make sure there are no conflicts between different versions of Windows.

Fixing “IRQL NOT LESS OR EQUAL” on Windows

Fix #1: Disable memory cache

To disable the memory cache of your Windows system, you need to enter in your computer’s BIOS/UEFI menu.

Follow these steps for Windows 8/8.1 systems so you can open the UEFI menu:

  1. Start your Windows
  2. Press Windows key and the C key to open the Charm Bar
  3. Click Settings
  4. Go to Change PC Settings
  5. Select General
  6. Click Advanced Startup
  7. Click Restart Now
  8. Go to Troubleshoot
  9. Select Advanced Options
  10. Click UEFI Firmware Settings
  11. Select Restart

Once you’ve entered the BIOS/UEFI menu of your system, follow these steps:

  1. Go to the Advanced Menu. Depending on your BIOS/UEFI version, this menu may have a different name.
  2. Find the Cache Memory option
  3. Hit Enter
  4. Select Disabled
  5. Press F10 to Save & Exit your changes
  6. Restart your computer

Fix #2: Install latest updates

In some cases making sure your Windows 8/8.1 has all the latest updates installed might fix the IRQL NOT LESS OR EQUAL error. Make sure your Automatic Updates option is turned on.

Follow these steps to check:

  1. Start Windows
  2. Windows Vista, 7 users can type update in the search box to open Windows Updates.
    Windows 8 users can open the Charm Bar by pressing Windows key and the C keys and then go Settings > Change PC Settings
  3. Click Update and Recovery
  4. Click Choose how updates get installed
  5. Select Install updates automatically
  6. Check Give me recommended updates the same way I receive important updates check box under Recommended updates
  7. Click OK
Windows Update and Recovery screen

Windows Update and Recovery screen

Fix #3: Clean boot

If the RQL NOT LESS OR EQUAL error is caused by a current running process, restart your Windows system using the clean boot method will allow you to troubleshoot if a current service or process is causing the error to appear.

With a clean boot only the necessary services and process that are required to operate Windows are started when you boot your computer.

Follow these steps:

  1. Start Windows
  2. Open Run. Windows 8 users can press the Windows key and R Key to open Run.
  3. Type msconfig and press Enter
  4. Go to General tab > check Selective Startup option
  5. Uncheck the Load startup items check box
  6. Go to Services tab
  7. Check Hide all Microsoft services check box from the bottom left corner of the window
  8. Click Disable all
  9. Click OK
  10. Restart Windows

To reset these changes and start your Windows normally, follow the same steps:

  1. Go to the General tab
  2. Check the Normal Startup option
  3. Click OK
  4. Restart
Msconfig settings screen

Msconfig settings screen

Fix #4: Remove unnecessary devices

A general fix for this error to remove all unecessary hardware devices from your computer and test if it boots correctly. If it does, one of your hardware device might trigger the IRQL NOT LESS OR EQUAL error to appear.

Remove all the unnecessary hardware devices like peripherals, USB devices, and any other devices that your computer can run without.

More Information

Support Links

Applicable Systems

This Windows-related knowledgebase article applies to the following operating systems:

  • Windows XP (all editions)
  • Windows Vista (all editions)
  • Windows 7 (all editions)
  • Windows 8 (all editions)
  • Windows 8.1 (all editions)

Propose an edit