driver_irql_not_less_or_equal (Netio.sys) blue screen Windows 8.1

Abhishek Dabas asked on
I updated my computer to Windows 8.1 a week ago and I kept on getting  Driver_irql_not_less_or_equal (Netio.sys) ERROR in a Blue Screen.I uploaded the minidump files to rapidshare: and system informtion: .Please help
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Patrick Barker replied on

All of the attached DMP files are of the DRIVER_IRQL_NOT_LESS_OR_EQUAL (d1) bug check.

This indicates that a kernel-mode driver attempted to access pageable memory at a process IRQL that was too high.

A driver tried to access an address that is pageable (or that is completely invalid) while the IRQL was too high. This bug check is usually caused by drivers that have used improper addresses.

By default, it's fauling NETIO.sys which is the Network I/O Subsystem. This is not the true cause and is being faulted by something else. Usually, in most cases, this occurs frequently in Windows 7 > 8 or 8 > 8.1 updates because of two reasons:

1. Network drivers themselves need to be updated.


2 (more common): 3rd party antivirus, firewall software or other software is causing conflicts and or corruption.


xpc4drvr.sys - Tue May 08 14:54:53 2007

^^ Xilinx microprocessor driver. Dated from 2007 which is far too old for Windows 8.1 compatibility. I would uninstall this software ASAP and/or remove the device along with it.

If after the above you're still having crashes, let's go ahead and enable Driver Verifier:

Driver Verifier:

What is Driver Verifier?

Driver Verifier is included in Windows 8, 7, Windows Server 2008 R2, Windows Vista, Windows Server 2008, Windows 2000, Windows XP, and Windows Server 2003 to promote stability and reliability; you can use this tool to troubleshoot driver issues. Windows kernel-mode components can cause system corruption or system failures as a result of an improperly written driver, such as an earlier version of a Windows Driver Model (WDM) driver.

Essentially, if there's a 3rd party driver believed to be at issue, enabling Driver Verifier will help flush out the rogue driver if it detects a violation.

Before enabling Driver Verifier, it is recommended to create a System Restore Point:

Vista - START | type rstrui - create a restore point
Windows 7 - START | type create | select "Create a Restore Point"
Windows 8 -

How to enable Driver Verifier:

Start > type "verifier" without the quotes > Select the following options -

1. Select - "Create custom settings (for code developers)"
2. Select - "Select individual settings from a full list"
3. Check the following boxes -
- Special Pool
- Pool Tracking
- Force IRQL Checking
- Deadlock Detection
- Security Checks (Windows 7 & 8)
- DDI compliance checking (Windows 8)
- Miscellaneous Checks
4. Select  - "Select driver names from a list"
5. Click on the "Provider" tab. This will sort all of the drivers by the provider.
6. Check EVERY box that is [B]NOT[/B] provided by Microsoft / Microsoft Corporation.
7. Click on Finish.
8. Restart.

Important information regarding Driver Verifier:

- If Driver Verifier finds a violation, the system will BSOD.

- After enabling Driver Verifier and restarting the system, depending on the culprit, if for example the driver is on start-up, you may not be able to get back into normal Windows because Driver Verifier will flag it, and as stated above, that will cause / force a BSOD.

If this happens, do not panic, do the following:

- Boot into Safe Mode by repeatedly tapping the F8 key during boot-up.

- Once in Safe Mode - Start > type "system restore" without the quotes.

- Choose the restore point you created earlier.
If you did not set up a restore point, do not worry, you can still disable Driver Verifier to get back into normal Windows:

- Start > Search > type "cmd" without the quotes.

- To turn off Driver Verifier, type in cmd "verifier /reset" without the quotes.
・    Restart and boot into normal Windows.

How long should I keep Driver Verifier enabled for?

It varies, many experts and analysts have different recommendations. Personally, I recommend keeping it enabled for at least 24 hours. If you don't BSOD by then, disable Driver Verifier.

My system BSOD'd, where can I find the crash dumps?

They will be located in %systemroot%\Minidump

Any other questions can most likely be answered by this article:


Debugger/Reverse Engineer.
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