You receive a "Stop error code 0x0000007F (UNEXPECTED_KERNEL_MODE_TRAP)" error message, or your computer unexpectedly restarts

This article helps to fix the error "Stop error code 0x0000007F (UNEXPECTED_KERNEL_MODE_TRAP)".

Original KB number:   822789


When you run Symantec AntiVirus Corporate Edition 8.0 and NSI Software's Double-Take, you may experience one or both of the following symptoms:

  • You receive the following Stop error message:

    STOP 0x0000007F (0x00000008, 0x00000000, 0x00000000, 0x00000000) (UNEXPECTED_KERNEL_MODE_TRAP)

  • Your computer unexpectedly restarts.


This issue may occur when your computer lacks sufficient kernel space to process kernel-mode drivers. The programs that are mentioned in the "Symptoms" section of this article install a kernel-mode driver and use a filter driver that registers with the kernel stack.

When Symantec AntiVirus or Norton AntiVirus file system real-time protection examines a file for viruses, it requests file access from the file system. These file input/output (I/O) requests can add to the kernel space that your computer consumes.


To resolve this issue, add the KStackMinFree value to the registry. The KStackMinFree value specifies the minimum kernel space that must be available for Symantec AntiVirus or Norton AntiVirus file system real-time protection to request file I/O from the file system.

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More information

For more information about "Stop x0000007F" error messages, click the following article number to view the article in the Microsoft Knowledge Base:

137539 General causes of STOP 0x0000007F errors

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