ErrorFindly
0x000000A4BSODCritical

0x000000A4 — CNSS File System Filter | Blue Screen Fix Guide

CNSS_FILE_SYSTEM_FILTER

Windows XPWindows VistaWindows 7Windows 8Windows 10Windows 11

What Does 0x000000A4 Mean?

An error occurred in the CNSS file system filter driver.

Real-World Causes

  1. 1File system filter driver bug
  2. 2Antivirus filter conflict
  3. 3Corrupted filter driver

Symptoms

  • ⚠Blue screen with stop code CNSS_FILE_SYSTEM_FILTER
  • ⚠System reboots unexpectedly
  • ⚠Possible data loss from unsaved work

DIY Fix

Beginner-friendly steps you can try at home

  1. 1Restart your computer
  2. 2Run chkdsk /f /r on the affected drive
  3. 3Run System File Checker (sfc /scannow)
  4. 4Check drive health with manufacturer tools

Advanced Fix

For experienced users and IT professionals

  1. 1Run chkdsk /f /r from Recovery Environment
  2. 2Analyze minidump for faulting file system driver
  3. 3Check S.M.A.R.T. data for drive health
  4. 4Consider drive replacement if errors persist

Frequently Asked Questions

What causes CNSS_FILE_SYSTEM_FILTER?
An error occurred in the CNSS file system filter driver.
Can I fix CNSS File System Filter myself?
In many cases yes. Start with basic troubleshooting like restarting, updating drivers, and running System File Checker. If the issue persists, advanced analysis of crash dumps may be needed.

Related Error Codes

0x000000F5FLTMGR File System0x00000022File System

About the Author

Windows Troubleshooting Team

Verified against official Microsoft documentation and real-world diagnostic data. Error behavior confirmed across Windows 10, Windows 11, and Windows Server.