If you’ve been using the Windows operating system for many years, you’re probably used to seeing Blue Screen of Death (BSOD) errors. However, no matter how familiar we’ve become with this agonizing curse, it still gets us blindsided. One of the many BSOD errors that users have been suffering from is 0xa4 CNSS_FILE_SYSTEM_FILTER. It periodically freezes a PC for a couple of seconds, then eventually, it will lead to a crash.

Now, if you’ve been affected by the same problem, you might ask, “What is the CNSS_FILE_SYSTEM_FILTER error?” Well, we’ll explain everything to you in this blog post. Keep reading and you’ll discover what causes it in the first place. What’s more, we will teach you how to get rid of the CNSS_FILE_SYSTEM_FILTER BSOD.

What Are the Causes of the CNSS_FILE_SYSTEM_FILTER Blue Screen Error?

Usually, the CNSS_FILE_SYSTEM_FILTER error shows up after a user has installed new software or hardware. The BSOD error may appear during program installation, while you’re loading a Windows driver, while a Microsoft-related software program is running, or while your operating system is booting or shutting down. It is crucial that you observe when the STOP error codes pop up because they will be useful in helping you troubleshoot the issue. In general, the BSOD error shows up in the following forms:

  • The CNSS_FILE_SYSTEM_FILTER bug check has a value of 0x000000A4. This bug check indicates that a problem occurred in the CNSS file system filter.
  • A problem has been detected and Windows has been shut down to prevent damage to your computer. The problem seems to be caused by the following file:
  • STOP Error 0xA4: CNSS_FILE_SYSTEM_FILTER

To learn how to fix the Error 0xa4, you need to know what causes the issue in the first place. Usually, the BSOD error shows up because of outdated, incorrectly configured, or corrupted drivers. On the other hand, it’s possible that a recent software change corrupted some keys in the registry. You should also check for viruses or malware because they can damage the system files critical in running the operating system. In some cases, the error has something to do with a damaged hard disk or RAM corruption.

Whatever caused the issue, we are here to help you fix it. Work your way down our list of solutions until you find the one that works best for you.

Method 1: Performing a Deep Virus Scan

As we’ve mentioned, the CNSS_FILE_SYSTEM_FILTER error may have something to do with a virus or malware infection on your PC. Essential system files may have been corrupted by these threats, causing the BSOD error to appear. As such, we recommend that you perform a full scan of your system. Here are the steps:

  1. Go to your taskbar, then click the Search icon.
  2. Type, “Windows Security” (no quotes), then press Enter.
  3. On the left-pane menu, select Virus & Threat Protection.
  4. Now, move to the right pane, then click Scan Options.
  5. Select Full Scan, then click Scan Now.

Wait for the process to complete, then restart your computer to check if the error is gone.

Method 2: Cleaning Out Your System

Your system stores temporary files locally, and eventually, they overload your OS and affect regular Windows operations. If you do not clean out these junk files, your OS will respond slowly and even cause the CNSS_FILE_SYSTEM_FILTER error. So, we recommend that you get rid of them. Doing so might resolve the problem and even improve the performance of your computer. To begin, follow the steps below:

  1. On your keyboard, press Windows Key+S to launch the Search box.
  2. Now, type “Disk Cleanup” (no quotes), then select Disk Cleanup from the results.
  3. Let Disk Cleanup calculate how much memory you can free up.
  4. Select Temporary Files and other components you want to remove.
  5. Click OK to proceed.

By the end of the process, you should have gotten rid of the temporary files. You must know that while Disk Cleanup is a useful built-in tool, it cannot wipe out all the temporary files on your computer. It is worth noting that this utility does not clean up other programs that you frequently use, including Chrome, Microsoft Office, Live Messenger, and more. So, we suggest that you use a program that is designed specifically for cleaning up PCs.

There are many cleaning manager tools out there, but Auslogics BoostSpeed is among the few that can promise comprehensive results. This tool has a powerful cleaning module that can sweep out all kinds of computer junk, including unneeded system and user temporary files, unused error logs, web browser cache, and leftover Windows Update files, among many others. It will even remove invalid entries and corrupt keys safely from the registry. Once the process is complete, you can expect a faster and smoother performance from your PC.

Method 3: Updating Your Device Drivers

The CNSS_FILE_SYSTEM_FILTER BSOD can also show up when there are outdated or corrupt drivers on your computer. Now, it can be difficult to identify the exact driver that may have caused the error. However, you can always update your drivers to fix any problematic driver. There are three ways to do this:

  • Via the Device Manager
  • Manual Download and Installation
  • Using Auslogics Driver Updater

Via the Device Manager

  1. Go to your taskbar, then right-click the Windows icon.
  2. Select Device Manager from the list.
  3. Once Device Manager is up, select the first category to expand its contents.
  4. Right-click the first device, then select Update Driver. Perform this step for all the entries under all the categories.

Manual Download and Installation

It is possible for your system to miss the latest updates for your device drivers. So, you may still end up downloading the drivers from their manufacturer’s website. However, you should be careful when you choose this method. If you download a driver that is incompatible with your operating system and processor, you may experience system instability issues. So, make sure that you download the right driver to avoid any problems.

Using Auslogics Driver Updater

Using the Device Manager can be time-consuming, and opting for a manual download and installation is risky. So, we suggest that you use a software program that’s specifically designed to update drivers. There are many tools out there for this purpose, but Auslogics Driver Updater is among the few that can promise convenience and reliable results.

You do not have to go through each driver because with one click of a button, Auslogics Driver Updater will take care of all problematic drivers on your computer. Once the process is complete, you can check if the CNSS_FILE_SYSTEM_FILTER BSOD is gone. As a bonus, you will notice a significant improvement in your PC’s performance.

Method 4: Performing a System Restore

One of the best ways to get rid of the STOP Error 0xA4 is by ‘going back in time’ and performing a system restore. You can bring your computer’s system files and programs back to a time when the issue did not exist. Don’t worry about your personal files because the process won’t affect them. To use the System Restore utility, follow the steps below:

  1. Go to your taskbar, then click the Search icon.
  2. Type “System Restore” (no quotes), then select Create a System Restore Point from the results.
  3. Once the System Properties window is up, click the System Restore button.
  4. On the next window, click Next.
  5. Make sure that the ‘Show more restore points’ box is selected.
  6. Now, select a restore point or date wherein the STOP Error 0xA4 did not exist.
  7. Click Next.
  8. Once the System Restore process is complete, restart your PC and check if the error is gone.

Method 5: Uninstalling and Reinstalling the Affected Program

If the CNSS_FILE_SYSTEM_FILTER BSOD shows up when you’re trying to run a particular program, we recommend that you uninstall and reinstall that app. Here are the steps:

  1. On your keyboard, press Windows Key+R.
  2. Inside the Run dialog box, type “Control Panel” (no quotes), then click OK.
  3. Select Programs.
  4. On the next page, click Uninstall a Program under Programs and Features.
  5. Now, look for the affected program.
  6. Right-click the app, then select Uninstall.
  7. After uninstalling the program, try to install it again, then restart your computer.

Once your PC boots, try running the program again and check if the error is gone.

Method 6: Performing an SFC Scan

If there are corrupt or damaged system files on your computer, you can fix them with the help of the System File Checker. This is a built-in Windows utility that repairs and restores missing or damaged system files. So, to get rid of the CNSS_FILE_SYSTEM_FILTER BSOD error, we suggest that you perform an SFC scan. To do that, follow the instructions below:

  1. Press Windows Key+S on your keyboard.
  2. Inside the Search box, type “command” (no quotes), then press Ctrl+Shift+Enter on your keyboard.
  3. If prompted to give permission to the app, click Yes.
  4. Once Command Prompt is up, type “sfc /scannow” (no quotes), then hit Enter.

Let the System File Checker locate and repair damaged, corrupt, or missing system files. Follow the on-screen instructions to complete the process.

Method 7: Installing Pending Windows Updates

If the STOP Error 0xA4 was caused by a bug, then Microsoft would probably have a fix for it. In this case, it is essential that you regularly install updates for your operating system. Windows should download the updates automatically in the background. However, there are times wherein you need to manually start the download. To do that, follow the steps below:

  1. Launch the Settings app by pressing Windows Key+I on your keyboard.
  2. Once you’re inside the Settings app, click Update & Security.
  3. Go to the left-pane menu, then click Windows Update.
  4. Move to the right pane, then click Check for Updates.
  5. If there are available updates, download them.
  6. Once the download is complete, restart your computer to install the updates.

Method 8: Using the CHKDSK Utility

Blue Screen of Death errors can also be caused by hard disk drive or storage controller issues. Because of repeated or unintended misuse, your computer may start to develop problems on the hard disk drive. Thankfully, Windows has a built-in utility called CHKDSK. You can use it to repair any hard disk corruption. So, if you want to learn how to fix the Error 0xa4, you must know how to run the CHKDSK command. Here are the steps:

  1. You need to open an elevated form of Command Prompt. To do this, click the Search icon on your taskbar, then type “Command Prompt” (no quotes).
  2. Right-click Command Prompt from the results, then select Run as Administrator from the context menu.
  3. If prompted to give permission to Command Prompt, click Yes.
  4. Once you’re inside Command Prompt, type “chkdsk /f” (no quotes), then hit Enter.
  5. Follow the on-screen instructions to complete the repair process.

Method 9: Performing a Clean Installation of Your Operating System

If none of the solutions helped you fix the error, then your final resort is to perform a clean installation of Windows. Remember to create a backup of all your important documents, photos, media files, software installers, and personal data before you perform this procedure. This solution will allow you to start with a fresh system. Consequently, you will erase everything on your hard drive, even the files that caused the error.

Are there other Blue Screen of Death errors that you’d like us to resolve?

Let us know in the comments below!