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

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Article ID: 822789 - View products that this article applies to.
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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. For instructions about how to add the KStackMinFree value to the registry, visit the following Symantec Web site:
Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice. Microsoft does not guarantee the accuracy of this third-party contact 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
The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products.


Article ID: 822789 - Last Review: January 26, 2012 - Revision: 4.0
  • Microsoft Windows Server 2003, Standard Edition (32-bit x86)
  • Microsoft Windows Server 2003, Enterprise Edition (32-bit x86)
  • Microsoft Windows XP Professional
  • Microsoft Windows XP Home Edition
  • Microsoft Windows 2000 Server
  • Microsoft Windows 2000 Advanced Server
  • Microsoft Windows 2000 Professional Edition
  • Microsoft Windows NT Server 4.0 Standard Edition
  • Microsoft Windows NT Workstation 4.0 Developer Edition
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