What is mrxsmb?

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

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

Mrxsmb.sys file information

The process known as Windows NT SMB Minirdr or MRxSmb belongs to software Microsoft Windows Operating System or SMB MiniRedirector Wrapper and Engine by Microsoft (

Description: The original mrxsmb.sys is an important part of Windows and rarely causes problems. The file mrxsmb.sys is located in the C:\Windows\System32\drivers folder. Known file sizes on Windows 10/8/7/XP are 453,120 bytes (23% of all occurrences), 456,576 bytes and 9 more variants. 
The driver can be started or stopped from Services in the Control Panel or by other programs. The program has no visible window. The file is a Microsoft signed file. It is a Windows core system file. mrxsmb.sys appears to be a compressed file. Therefore the technical security rating is 2% dangerous; however you should also read the user reviews.

Recommended: Identify mrxsmb.sys related errors

Important: Some malware camouflages itself as mrxsmb.sys, for example TrojanDropper:Win32/Sirefef.B (detected by Microsoft), and TROJ_GEN.R01C7DO (detected by TrendMicro). Therefore, you should check the mrxsmb.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

Used in windows when copying large network file
  Krusty23   (further information)
i don't know much about i just put the recovery in my laptop and now it has bluescreen with this msg: 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: mrxsmb.sys PAGE_FAULT_IN_NONPAGED_AREA
from microsoft clean install
  ZKS   (further information)
all I did was went into safe mode and deleted it, everything is working fine now
MRXSMB.SYS is responsible for SMB network operations
Used in windows when copying large network file
For info go to
  robin bailey   (further information)
blue screen while copyin file over a network an using icq: rdr_file_system
combofix repeatedly id'ing it as bad. combofix was run to get rid of malware causing IE to run in the background with a noisy japanese site. seems to be related to a fake Task Manager called 'taskmagr.exe'.
as i know then it's a System file of Windows .. and it maybe conflic with the svchost fle, hence it make your computer doom. If it appears more than one times, i think you should ghost your Windows :D ..... Sorry i make you confuse :D
  Thanh Binh  
follow the link there is a desciption ( UTFSE )
  Jerry   (further information)
Microsoft has a "Hot Fix" for this file when it is corrupted by a virus. This is the page that explains it: This is the page to request they email you the link: Here is the link to the file:
I remember SMB.sys from beta testing Windows NT but it didn't cause any problems then. Yes Windows NT was a server OS. Don't think it's dangerous just not needed in home computers unless you do large file downloads. I do believe that was it's purpose. I'm going to remove it and see what happens.
  J C Wallace  
In Windows 10 SMB seems to be used as a Network Dia. app.and you will find smb files in there. MS uses SMB for those who use the server side a lot.So be careful.Helps the network some how, like downloads and etc.
  J C Wallace  

Rating chart

Summary: Average user rating of mrxsmb.sys: based on 17 votes with 14 user comments. 9 users think mrxsmb.sys is essential for Windows or an installed application. 3 users think it's probably harmless. 3 users think it's neither essential nor dangerous. One user suspects danger. One user thinks mrxsmb.sys is dangerous and recommends removing it. One user is not sure about it.

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Best practices for resolving mrxsmb issues

A clean and tidy computer is the key requirement for avoiding problems with mrxsmb. 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, for Windows 8 and later versions, executing the 7DISM.exe /Online /Cleanup-image /Restorehealth command. This allows you to repair the operating system without losing data.

To help you analyze the mrxsmb.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. BMalwarebytes Anti-Malware detects and removes sleeping spyware, adware, Trojans, keyloggers, malware and trackers from your hard drive.

Other processes

mrxsmb.sys [all]