What is mrt.exe?

The genuine mrt.exe file is a software component of Windows by Microsoft.
Mrt.exe is the main executable used to run the Microsoft Removal Tool. It is not a core Windows process, but should only be removed in case it is causing problems. The Microsoft Removal Tool was first released in 2005 for the Microsoft Windows operating system. It is a freely available tool and it scans your computer for some of the most common infections. If you turn on Automatic Updates in Windows, this tool will be downloaded and run on the second Tuesday of each month. It runs silently in the background unless it finds an infection. This is an effective tool, but it cannot be considered a replacement for a real anti-virus program. Microsoft was founded in 1975 by Bill Gates and Paul Allen and quickly rose to prominence following the launch of their popular operating system, MS-DOS, for early personally computers. Today Microsoft develops many different products such as computer software, consumer electronics, personal computers and services.

MRT stands for Microsoft Removal Tool

The .exe extension on a filename indicates an executable file. Executable files may, in some cases, harm your computer. Therefore, please read below to decide for yourself whether the mrt.exe on your computer is a Trojan that you should remove, or whether it is a file belonging to the Windows operating system or to a trusted application.

Click to Run a Free Scan for mrt.exe related errors

Mrt.exe file information

Windows Task Manager with mrt
Mrt.exe process in Windows Task Manager

The process known as Microsoft Windows Malicious Software Removal Tool belongs to software Microsoft or Microsoft Windows Malicious Software Removal Tool or Microsoft Windows Malicious Software Removal by Microsoft (

Description: Mrt.exe is not essential for Windows and will often cause problems. Mrt.exe is located in the C:\Windows\System32 folder. The file size on Windows 10/8/7/XP is 13,179,660 bytes. 
The mrt.exe file is certified by a trustworthy company. Mrt.exe is not a Windows system file. The program has no visible window. Mrt.exe is able to monitor applications and manipulate other programs. Therefore the technical security rating is 22% dangerous; however you should also read the user reviews.

Uninstalling this variant: If problems with Microsoft Corp. or Microsoft Windows Malicious Software Removal occur, you can contact to assist you or remove the entire program using Windows Control Panel.

Recommended: Identify mrt.exe related errors

Important: Some malware camouflages itself as mrt.exe, for example TROJ_GEN.R03BC0OC318 or TROJ_GEN.R002C0OCP18 (detected by TrendMicro), and ML.Attribute.HighConfidence or Trojan.Gen.6 (detected by Symantec). Therefore, you should check the mrt.exe 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 seemed to have the effect of slowing my comp down, almost to stand still. When I removed it from running processes, the computer sprang back into action.
mrt comes from you bum bum
It uses all the cpu on my laptop. Not dangerous, or essential. When i disable it out of task manager my laptop runs faster. I am usng a Pentium M, 1.4 GHZ. Hwever if you have a faster machine with a dual core, you may not have to remove the program since your computer is light years ahead of the current one that I am using.
it's a tool to remove hazardes virus etc, from your computer it's from microsoft...
mrt.exe is a process belonging to Microsoft's enhanced security technologies which addresses Spyware and other processes which can monitor your Internet usage without your knowledge. This process is important for safe and secure Internet browsing and shouldn't be terminated.
  Brent Bice   (further information)
oooo it is the short form of windows malicious software removal tool and it is completely safe
It's Windows Malicious Software Removal Tool
  Hacker   (further information)
Microsoft anti-virus, anti-trojan, anti-worm tool runs in background and slows the machine.
If its the Microsoft file for Malicious Software removal tool, its critical to keep it in place but it doesn't always run. Just wait for it to finish and then your computer will speed up again. It keeps you safe. It only runs once a month people!
  Typegeek   (further information)
its a solution to remove trojans and worms
MRT i was searching to find out what it was. I was installing ie8 at the time and it was Searching For MAlacious Software. I Ended the process and the check failed on the update so i guess it is from microsoft.
Also slowed my laptop to a crawl
  Curt Thompson  
if located in the system32 folder then it is probably adware and trojan downloader, remove it asap in that case
Never seen it before today but damned if it didnt stop my PC dead in its tracks. PC ran fine once I ended its process now I am gonna remove it all together. I will say dangerous because a slow PC is bad for your mental health & who knows what data it is shooting back to MS
  I Hate Windows but it works  
ive never actualy had mrt find a virus but i trust it to do its job if i do get one
Seems to be part of ms's malicious removal software included in windos update. It usually searches the computer for hazardous software. When complete it stops and wont run until next update (about once a month). In some cases it might crash, and use 100% of cpu all the time, and might keep running every reboot until its task is completed. MRT is not an essential application nor is it dangerous, however its could still be nice to have just in case....
  Dan -K  
Part of Norman Malware Removal Tool- freeware and trustworthy. Should be run in safe mode
  Eric Leinbach   (further information)
Microsoft Windows Malicious Software Removal Tool
  Nick (Almere)   (further information)
Malicious Software Removal Tool from Microsoft. Not essential and a drain on resources.
Turns computers into slugs when you need speed
malicious removal tool
When I was online surfing the web I noticed my computer was slowing down alot for no reason! I was trying to load a page and it took forever. I figured Firefox was just using up alot of CPU usage, but I was wrong. I checked my Task Manager and noticed a file running called "MRT.exe" which I had never seen before. It was soaking up all my CPU usage. I wasn't sure if I should end the process or not. So I went on to Google and searched "MRT.exe" and I am reading all these diffrent reviews on whether it is dangerous to my computer or not. Alot of people are saying there is nothing to worry about.
It started after I did Windows update... Though it takes up a lot of resources, it didn't seem to affect anything afterwards.
ohh its the malware removal tool for windows,
Windows program
  A. B.   (further information)
it's a system component.
  JFX   (further information)
Task manager did not starts, tskill MRT.exe does not work, tasklist.exe never ends. May be ofice spyware
cames and goes when running automatic updates just let windows do it's thing for a while and it will go away (well most of the time)
Windows Malicious Software Removal Tool. Works in the background removing malware when it finds it, but if you want to run it in interactive mode, type mrt.exe in the Start Menu Search Box or in the Run window.
  foobar   (further information)
It comes with installing Windows Internet Explorer 8. It's required from microsoft...
slowing donw, disable possible
I found it on removable flash drive F
  randy nelson  
Mircosoft`s malcius software removal tool
Malicious Software Removal Tool from Microsoft
I have an external (backup drive). I checked the drive contents and see my back up there, but there are also about 8 or 9 folders that have a very long random set of numbers and letters. Each of those folders have MRT.exe in it. So, I have numerous instances of it. I guess that it somehow downloads onto the external drive every month or so. It doesnt seem to do anything, and I never see it running.
It is the Windows Malicious Software Removal Tool. It is not malicious, and it is not a vital process
On my PC, it works with mrtstub.exe and a process called something like windows-(numbers and letters) because they disappear (all the 3) when I remove MRT from ym running processes. But MRT.exe is the only that uses 100% CPU or near and my old PC slows down. I don't know much about it, it seems to be a malware for me, but it can be false!
windows malisious software tool
  Just Me  
Belongs to malicious removal tool from microsoft.You can find it to system 32 folder.Starts automatically by microsoft when you install the MSRT
It's Microsoft's Malicious Software Removal Tool, but it can slow your computer down. Let it run for a minute or two and it'll go away.
When it acts funny it's probably something disguised as MRT.exe maliscious software remove tool
My audio mysteriously quit working on the same day this program was installed.
I was rather annoyed when my computer was crawling and all I was doing was ebay. I checked the task manager and MRT.exe was occupying nearly 200mb's of my RAM. I looked it up and found this wonderful page. One of the first user comments said just let it do its thing cause it's just checking some stuff for viruses and it's from microsoft as a part of the malicious software removal junk they're constantly sending updates to us for. As I read, it finished up whatever it was doing and went away on it's own. *shrug*
  Mikey Bear  
I ran it quick scan it found nothing, I ran free malwarebytes which picked up 4 and also super antispyware which picked up 11 (still running as well). if its not good for anything but slowing down systems then I think we should get rid of it. Also found 4 other folders under temp numeric/alphabetical long names with it in as well.
I found files with this name in several locations on my machine, but not any of the places listed above. although they are proportedly from microsoft they do not match the file sizes given above (these are far far bigger). I'm really not sure what to do.
MRT: Malicious-software Removal Tool. Let it run, it will scan your PC then won't run anymore until the next windows update. (Unless set to autostart by an administrator.)
Norton Antivirus scan
I have 6 different MRT.exe files all about the same size
Talk about a resource hog, big time! I have a 1.8Ghz dual core laptop which was virtually unusable till I disabled MRT. exe Microsofts answer to a threat - BLOATWARE
  The Narseman  
It caused problems for my computer and stopped it cold. It ran the system processes 100% and didn't stop until I terminated it manually.
  Tom J  
it's get my uers at 100%
  freddie simmonds   (further information)
first time i saw it running was 2-3 days ago.....It showed me that i have about 1000 infected files of the 1 million it scanned. (i didn't know i had that much).When it stopped scanning for infected files, it showed me a window and told me that the program can remove the threats.but it freezes without doing nothing when it reaches that.
MRT.exe on my XP Asus Eee netbook with precious little room has a filesize of 48.324.552 bytes.
  Robert C. VanWaning  
The size of mine was different from anything mentioned above, so I downloaded a new copy from Microsoft to be certain I had a good copy. It had the same size: 54,867,776 bytes, dated December 07, 2011. The file size probably changes as not malicious software is added to what is checked.
  Victor   (further information)
Evil or not was consuming 98% of my single core cpu, win XP, if is a tool from Microsoft thei should make those tools invisible to user, dooh, i killed the process and deleted the file. Fixed.
Naffed up PC a couple of days after an auto update from MS (which I set to inform me of updates so I can choose to install or not, but every now and then MS seems to overide the setting. On this occasion, it even re-started my PC on it;s own!).
It slows down a computer incredibly. One of my colleagues had this on his laptop, making it practically unusable (e.g. opening Explorer took about 30 seconds instead of 1 second). Once the process was killed, the laptop worked normally. It might be benevolent, but renders a computer unusable.
  Gregory K.  
could not remove or stop it the 'usual' way so I removed it via the registry startup menu. Before my HDU stumbled around wild in half an our and I had a black screen never to return live. My MRT.exe sample was definitly malware
It was running when I was receiving an update from M$. Once the update was in, it shut off by itself.
  Pete Dvarackas  
Was running with high cpu load for some time. Dissapeared as the windows update popped up.
  Yngve T  
Slows down my computer
Legitimate but obnoxious malware removal tool by Windows. Classic Microsoft software: a bloated resource hog whose job is done better and cheaper by independent programmers. Don't rely on this paper tiger of a program and get yourself a real anti-malware program.
  SysAdmin Prime  
Well its from microsoft and it is a thing that helps removes malious
MRT for Vista size on disk 69.9 mb
Its safe
I have XP Professional, and on my system MRT works just like an application. I double clicked the .exe file in system32 and it opened into a little window saying what it was and asking if I wanted to scan my computer. After the scan was done I exited the window and the process stopped, not running in the background. Seems a fine secondary antivirus scan if you want it.
  Jonathan P  
i noticed it recently, and since i have my computer seems very slow. have found many conflicting views on it online. norton does not detect anything wrong with it but i am still suspicious. it is 72.2 megabytes and contained inC:\WINDOWS\system32 on my old xp machine.
if it location is in %windir%\system32 and if cliced on it and chose propertis and there is indicated that it is application of MIcrosoft etc and it is signet by Microsoft then this is The Microsoft Windows Malicious Software Removal Tool
  darko555   (further information)
found a 78.106.760 byte MRT.EXE after installing open office 4.0.1 eating 35% of my CPU
  Reinier Bakels  
This program can be hijacked by malicious software. Any form that is above 20,000mb should be checked. It's a good idea to set a system restore point, and have a plan in case the hijacker fights after deletion.
  Mal-Review Expert Mathew  
I have about 4 of these files in my "C" folder under things like "093923715c4cda27d5d". Can I get rid of 3 of 'em?
It is worse than just making the computer slow. Runs the CPU temperature up to 85 celsius and crashes the computer.
I discovered MRT.exe in location D:\ce7fa014e0de8096c10782de6aca50. it is told that it should be on C:/windows/system32 but it has another location.
I found it by it's self in my windows c drive under a long number f1be32f8d4le32db2445. I mover my cuser over and it put some details in a little window and said it was mrt.exe didn't see it in my system 32 fine.
MRT.exe is an important part of Windows update. It scans for malware and removes it. To keep tabs on what it has done look at %systemroot%\debug for the file mrt.log. Examine it to see details of each time it has run. (This page gives 44% recognition of this fact (31/71), in other words 56% of opinions are suspect. Incredible!!)
  Vladimir Tchepes   (further information)
Came with recent windows update installs. MRT.exe is Microsoft's "Malicious Software Removal Tool". It scans for infected files. Running it now, since I had a very annoying trojan, the first virus I've had in 12 years. Had to do most of the removing manually. Computer is still running slower (not counting when MRT.exe is scanning). Tried disk cleanup, msconfig, optimize windows, adjust for best performance, deleted unused programs, reset firefox, hardware acceleration, ran chkdsk, ran AVG full system scan, quarantined 5 files, ran Malwarebytes, full system scan, now running disk defrag and hoping I don't have to reformat. Whomever created the OpenCandy trojan should be shot execution style in the back of the head.
It seems to clog up a ton of memory (RAM). I have a 1GB laptop though :(
This thing showed up today (5/17? under my C: drive but says it was installed on 1/16. I have never seen it before today. It's listed under c: as 6609c46456b652f869991c88fb6de3 and upon looking at the 3 files within it, one says mrt.exe._p (5,519 KB). the other file is $shtdwn$.req (1kb), the other file is mrstub (79kb). I can't find any info on this except it saying it's ok if it's in the system32 folder or it's part of the mailicious tool remover which I did just get an update on last night. Still, I'd love to know what's up with this.
This was very helpful. The installation process had remained at 0, not uncommon but longer than usual. It completed as I was reading these remarks.
  Paul Kabelo  
My MRT.exe located in C:\WINDOWS\system32 is sized 119.837.696 bytes and results modified and accessed today march 11th 2015. File version 5.22.11202.0. Digital signature timestamped Feb 27th seems ok. But it hangs up my PC, I killed it from task manager to run normally.
  Fabrizio BASSI (sbriXio)  
MRT.exe is a malicious, dangerous application, which runs silently in the background without your knowledge.
  Andy Smith  
Microsoft Malicious software Removal Tool.
On my old vista machine, in the root of C drive there are about 6 randomly named folders with MRT.exe in each of them. Checking the properties, they're not associated with microsoft so i suspect that this is one of the viruses wreaking havoc on the machine.
Running Windows 8 MRT.exe was updated on 14 May 2015 and it's size is 140,427,016 bytes
There are reports about MRT.exe log keys (HKLM\SOFTWARE\Microsoft\Windows NT\Current Version\Image File Execution Options\MRT.exe and HKLM\SOFTWARE\Wow6432Note\Microsoft\Windows NT\Current Version\Image File Execution Options\MRT.exe) belong to Trojan.FakeAV (used Hitman Pro software)
I suggest that you uninstall MRT then re-download it (use the provided link)
  SuperUser   (further information)
Since you shouldn't use this as your default spyware/virus/trojan protection, this program is really not needed. It doesn't do anything fancy, just slows stuff down and is a waste. Might as well disable it.
MS Removal Tool - AVG is flagging as a I must investigate if it is the genuine file or it has been replaced with a trojan
Harmless may or not be removed it is a user preference. One thing I have found is it should be disabled in the task scheduler even if it states that it has never been run. Leaving this enabled Slowed my startup on all three computers a little. It does run when Microsoft updates it as said in some of the other posts on this subject. You may uninstall it or keep it.
  Chris Cummings  
MRT.exe when it tries to run my Avast Firewall blocks it. It tries about 40 times in one day to access my system. So i just deleted the EXE file and it's in mt Trash can. If i have a problem I'll restore it.
If mrt.exe is not located in the system32 folder, it's a virus. One day, the program was running and I didn't knew it. This program ends processes and screws up the program that was closed. For example: I left WordPad open because I needed to do some homework, then the program was closed and I couldn't open it anymore
its just remove my google sketchup when i work.when i doo my job on sketchup,the program just close and when i try to restrart the program its not in the comp.i have only the desktop shortcut and in task manager its this mtr.exe, new.i never see it till now

Rating chart

Summary: Average user rating of mrt.exe: based on 127 votes with 93 user comments. 41 users think mrt.exe is essential for Windows or an installed application. 21 users think it's probably harmless. 35 users think it's neither essential nor dangerous. 19 users suspect danger. 11 users think mrt.exe is dangerous and recommend removing it. 24 users don't grade mrt.exe ("not sure about it").

Do you have additional information?

Best practices for resolving mrt issues

A clean and tidy computer is the key requirement for avoiding problems with mrt. 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 mrt.exe 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

mrt.exe [all]