KMODE_EXCEPTION_NOT_HANDLED bug check has a value of 0x0000001E. In layman terms, this means that a kernel-mode program generated an exception which the error handler did not catch. It often results from the display of blue screen while a user is attempting to install a program or any of the Windows drivers that have just been loaded at startup or shutdown. Also, an incorrectly configured device driver can cause this type of error. There’s no single source that can be attributed to the main cause of this error. As such, it is difficult to pinpoint or troubleshoot this problem. However, keeping track of when and where your STOP Error occurs, can help in troubleshooting the problem.

The Windows kernel detected an illegal or unknown processor instruction is usually the result of invalid memory and access violations caused by Hardware incompatibility, Faulty device driver or Faulty system services. The error message often identifies the offending driver or device. If the error occurred immediately after installing a driver or service, try disabling or removing the new addition.

KMode Exception Not Handled, CLASSPNP.SYS failed


In the above image, it says that the file CLASSPNP.SYS failed. This is an SCSI Class System DLL driver file and the location of this file is C:\Windows\System32\drivers\classpnp.sys.

1] SCSI Class System Dll Microsoft Windows OS file

Most SYS files allow internal PC hardware or attached hardware, such as a printer, to communicate with third-party software programs (e.g. web browsers, word processors, MSDN Development Platform U.S.) and the operating system (e.g. Windows).

Other SYS files are critical system files called “kernel mode device drivers” which are used to power the Windows operating system. Files such as “CONFIG.SYS” contain configuration settings and specify what device drivers should be loaded by the operating system. Without driver files such as CLASSPNP.SYS, you wouldn’t be able to do simple tasks such as printing a document. Any sort of corruption of this file can create errors such as in the form of KMODE_EXCEPTION_NOT_HANDLED.  It is therefore advisable to scan your PC for CLASSPNP.SYS file corruption.

Run System File Checker or sfc.exe to scan for and restore corrupt Windows system files.

2] Windows 10 Blue Screen Troubleshooter

Opens the Blue Screen Troubleshooter via Settings > Update & Security > Troubleshoot and run it and see if it helps.

3] Disable Fast Startup

You may disable Fast Startup and see if that helps.

4] Visit the online Blue Screen Troubleshooters web page

Visit the Microsoft site to run the online Blue Screen Troubleshooter. You will see a simple wizard that will walk you through the process of troubleshooting Blue Screens.

You will first be asked – When did you get the blue screen error?

  1. While upgrading to Windows 10
  2. After an update was installed
  3. While using my PC.

Select your options as and when they are asked, and hopefully, you will get the proper guidance on what needs to be done.

5] Update device drivers

Installing the wrong driver, or configuring an incompatible version of the right driver can cause the error. So, it is essential to check and install the right version of the required driver. Refer to our post – Uninstall, Disable, Roll Back, Update Device Drivers for more information.

I am sure something here will help you. If this does not help you, there are some more tips to help you fix Blue Screen of Death in Windows 10 under different scenarios. If you need more detailed help, check out this detailed BSOD guide.

If you are a system administrator and equipped to debug this problem, visit

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The author Hemant Saxena is a post-graduate in bio-technology and has an immense interest in following Windows, Office and other technology developments. Quiet by nature, he is an avid Lacrosse player. Creating a System Restore Point first before installing a new software, and being careful about any third-party offers while installing freeware is recommended.

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