What is MpFirewall?

MpFirewall.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 MpFirewall.sys is a Windows system file or if it belongs to an application that you can trust.

Run a free scan to check for MpFirewall drivers in need of updating

MpFirewall.sys file information

The process known as McAfee Personal Firewall Driver or McAfee Personal Firewall Plus (version 6.1, 5.0) or MPFIREWL belongs to software McAfee Personal Firewall or McAfee Personal Firewall Plus or MPFIREWL by McAfee ( or McAfee Security (

Description: MpFirewall.sys is not essential for Windows and will often cause problems. MpFirewall.sys is located in the C:\Windows\System32\drivers folder. Known file sizes on Windows 10/8/7/XP are 80,640 bytes (77% of all occurrences), 67,584 bytes, 55,936 bytes, 83,325 bytes or 72,461 bytes. 
The driver can be started or stopped from Services in the Control Panel or by other programs. The program is not visible. There is no detailed description of this service. It is not a Windows core file. MpFirewall.sys appears to be a compressed file. Therefore the technical security rating is 39% dangerous, however you should also read the user reviews.

Uninstalling this variant: You might want to uninstall McAfee Personal Firewall Plus software via Windows Control Panel/Add or Remove Programs (Windows XP) or Programs and Features (Windows 10/8/7).

Recommended: Identify MpFirewall.sys related errors

Important: Some malware camouflages itself as MpFirewall.sys. Therefore, you should check the MpFirewall.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.


User Comments

It caused the blue screen of death to come up! address b2ec3a8f, base b2ec1000, datestamp 409a669f
  Deborah Vernon  
BSoD on Windows XP (Media Center). Brand new PC, has happened 3 times in 2 days... always when logging on.
  Lorenzo Vicente  
Permanente Systemabst├╝rze: z.B. Adresse ABC9F395
  S. Bachmann  
This is the main driver for the firewall
  Greg Finzer  
Has caused blue screen of death twice in first 2 days of owning new pc
It caused BSoD to appear on boot-up (Windows XP) with message (WDM DRIVER ERROR 21F
McAfee's firewall, Causes Blue Screen of Death (BSoD) on my friend's PC... caused the BSoD's as soon as she got the PC (from Dell), came ready installed... tried to reinstall and update McAfee, didnt help... still got random BSODs every few days... ended up deleteing it
Will BSoD Upgrade to Vista Business
  John K   (further information)
Causes BSOD's especially when installations occur (windows upgrades, msoffice etc). I disabled the services whilst I installed but if I had the choice I would uninstall McAfee and use something that is freeware and less bloatware etc.
Kept getting blue screen death. Uninstalled McAfee firewall & now my pc is fine
  Andy Joseph  
Caused BSOD while doing Microsoft Update on brand new dell laptop.
  Chris Darrow  

Rating chart

Summary: Average user rating of MpFirewall.sys: based on 10 votes with 11 user comments. 2 users think MpFirewall.sys is essential for Windows or an installed application. One user thinks it's neither essential nor dangerous. 7 users suspect danger. One user is not sure about it.

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Best practices for resolving MpFirewall issues

A clean and tidy computer is the key requirement for avoiding problems with MpFirewall. This means running a scan for malware, cleaning your hard drive using cleanmgr and sfc /scannow, uninstalling programs that you no longer need, checking for Autostart programs (using msconfig) and enabling Windows' Automatic 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 resmon 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, for Windows 8 and later versions, executing the DISM.exe /Online /Cleanup-image /Restorehealth command. This allows you to repair the operating system without losing data.

To help you analyze the MpFirewall.sys process on your computer, the following programs have proven to be helpful: Security 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. Malwarebytes Anti-Malware detects and removes sleeping spyware, adware, Trojans, keyloggers, malware and trackers from your hard drive.

Other processes

MpFirewall.sys [all]