What is CLFS?
The genuine CLFS.sys file is a software component of Microsoft Windows Operating System by Microsoft Corporation.
"CLFS.sys" is Microsoft's "Common Log File System Driver", located in "C:\Windows\System32\drivers". It is an essential Windows system file and if it is missing or corrupted Windows will fail to start, resulting in a blue screen error message. The Common Log File System (CLFS) is available to kernel-mode and user-mode client modules which call it to maintain event or transaction history, including the Windows event logs recording what occurs as Windows operates. Log files are extremely important to database or financial applications using "atomic" transactions, where failure of one event may mean other events must be backed out.
CLFS stands for Common Log File System Driver
CLFS.sys is a Windows driver. A driver is a small software program that allows your computer to communicate with hardware or connected devices. This means that a driver has direct access to the internals of the operating system, hardware etc.
The free file information forum can help you determine if CLFS.sys is a Windows system file or if it belongs to an application that you can trust.
Run a free scan to check for CLFS drivers in need of updating
CLFS.sys file information
The process known as Common Log File System Driver belongs to software Microsoft Windows Operating System by Microsoft (www.microsoft.com).
Description: The original CLFS.sys is an important part of Windows and rarely causes problems. CLFS.sys is located in the C:\Windows\System32 folder.
Known file sizes on Windows 10/11/7 are 244,152 bytes (50% of all occurrences), 250,560 bytes, 247,352 bytes or 249,408 bytes. 
The driver can be started or stopped from Services in the Control Panel or by other programs.
The CLFS.sys file is a Windows core system file. CLFS.sys is a trustworthy file from Microsoft. The file has a digital signature. The program has no visible window.
CLFS.sys appears to be a compressed file.
Therefore the technical security rating is 0% dangerous; however you should also read the user reviews.
Uninstalling this variant:
If problems with
Microsoft Windows occur, you may also want to uninstall the associated program (Start > Control Panel >
Uninstall a Program) or ask for help from
Support.
Recommended: Identify CLFS.sys related errors
If CLFS.sys is located in the C:\Windows\System32\drivers folder, the security rating is 0% dangerous. The file size is 275,352 bytes (50% of all occurrences) or 279,384 bytes.
The file is a Windows system file. It is a Microsoft signed file. The program is not visible.
CLFS.sys appears to be a compressed file.
Important: Some malware camouflages itself as CLFS.sys. Therefore, you should check the CLFS.sys process on your PC to see if it is a threat. We recommend Security Task Manager for verifying your computer's security. This was one of the Top Download Picks of The Washington Post and PC World.
Best practices for resolving CLFS issues
A clean and tidy computer is the key requirement for avoiding problems with CLFS. This means running a scan for malware, cleaning your hard drive using 1cleanmgr and 2sfc /scannow, 3uninstalling programs that you no longer need, checking for Autostart programs (using 4msconfig) and enabling Windows' 5Automatic Update. Always remember to perform periodic backups, or at least to set restore points.
Should you experience an actual problem, try to recall the last thing you did, or the last thing you installed before the problem appeared for the first time. Use the 6resmon command to identify the processes that are causing your problem. Even for serious problems, rather than reinstalling Windows, you are better off repairing of your installation or executing the 7DISM.exe /Online /Cleanup-image /Restorehealth command. This allows you to repair the operating system without losing data.
To get your computer running as fast as it did on day one, you can 8reset your PC. Your personal files will remain intact, but any programs you installed will need to be reinstalled.
To help you analyze the CLFS.sys process on your computer, the following programs have proven to be helpful: ASecurity Task Manager displays all running Windows tasks, including embedded hidden processes, such as keyboard and browser monitoring or Autostart entries. A unique security risk rating indicates the likelihood of the process being potential spyware, malware or a Trojan. A good Bantivirus software detects and removes sleeping spyware, adware, Trojans, keyloggers, malware and trackers from your hard drive.
Other processes
leagueclientuxrender.exe frameapplethook.x32.dll umbus.sys CLFS.sys audialsnotifier.exe wisptis.exe bprotect.exe shellext.dll defenderdaemon.exe averscheduleservice.exe rpcss.dll [all]
Score
User Comments
Ken R.
Summary: Average user rating of CLFS.sys: based on 1 vote with 1 user comment. One user thinks CLFS.sys is essential for Windows or an installed application.