What is msmpeng.exe and how to remove it

Posted by Aseem on Monday, March 23rd 2009

23
Mar

Has your processor been at 100% utilization lately? If you went to the Task Manager in Windows and looked at your processes tab, you may have noticed a process called msmpeng.exe eating up all your available CPU.

So what is msmpeng.exe and how can you prevent it from slowing your system down? Well, unlike what you may have read elsewhere, it is not spyware or malware. It’s actually quite ironic because it’s associated with Windows Defender, the anti-spyware product from Microsoft.

Unfortunately, this crappy piece of software is already installed on Windows Vista and it also comes with Windows Live One Care. There are two ways to stop msmpeng.exe from using system resources: exclude the Windows Defender directory from scanning or simply turn off Windows Defender.

Exclude directory for scanning

If you would like to keep using Windows Defender, then your only chance of fixing the high processor usage issue is to prevent the Windows Defender directory from being scanned.

Apparently, the service scans it’s self and therefore eats up all the CPU. Open Windows Defender, click on Tools and then Options. Now scroll down to the Advanced Options section:

Now click on the add button under the “Do not scan these files or locations” section. Now type in the path for the Windows Defender directory:

c:\program files\windows defender

Click OK and now make sure to click the Save button. Hopefully this will fix your high CPU usage error with Windows Defender. Also be sure to read my post on how to customize all the options for Windows Defender like what stuff to monitor in real-time, etc.

Turn off Windows Defender

The other option is to simply turn off Windows Defender, which I think is a better idea anyway. There are lots of other spyware programs out there that are much better than Windows Defender.

To turn off Windows Defender, open the program and click on Options. Now go to Administrator options and uncheck the Use Windows Defender box. Make sure to click Save.

So that’s it! msmpeng should now no longer be messing up your system. If you’re still having troubles, post a comment here. Enjoy!

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28 Comments Already

IMCAmodRacer Said,

May 5th, 2009 @9:12 am

How do I stop it through OneCare?

Bill Said,

October 1st, 2009 @6:29 am

My CPU was eating(?) my computer all the time. Just followed your advice and CPU is now using 2% instead of 98%.
Brilliant..!

Mike Said,

November 1st, 2009 @4:04 pm

I liked this usefull information.

You wrote; the other option is to simply turn off Windows Defender, which I think is a better idea anyway. There are lots of other spyware programs out there that are much better than Windows Defender.

Which spyware programs are you talking about…if I’m using them then I’ll want to turn off windows defender, too.

Thanks. Mike

Paul Said,

December 21st, 2009 @6:01 pm

Thanks. This msmpeng.exe process was slowing the pc down to a crawl. Merry Christmas and Happy New Year.

rogy Said,

January 5th, 2010 @8:19 pm

I have Windows Defender uninstalled (WinXP) and msmpeng.exe is still gobbling up resources. Could MSE (Microsoft Security Essentials) be using the service instead? Can it just be turned off in msconfig?

sporkit Said,

January 13th, 2010 @11:41 pm

If disabling like mentioned above doesnt work try win+r, services.msc, ok, then disable the windows defender services from the list.

JudyBee Said,

January 16th, 2010 @9:13 am

Thanks! went from 100% CPU usage down to 12 – thanks again.

mgear Said,

January 23rd, 2010 @11:21 am

Microsoft Forefront Client Security has this problem, as well. I adjusted your instructions, and using the Forefront settings, excluded the directory within the Forefront program folder that has MsMpEng.exe in it.

Thanks so much for your post. The suggestions on a number of other pages did not help me at all.

Jason L Said,

February 3rd, 2010 @7:58 am

Thanks for this article! I was wondering what msmpeng.exe was and why it was eating up all my CPU cycles!

Michael M Said,

February 3rd, 2010 @1:37 pm

I’m running WindowsXP with Microsoft Security Essentials and I also have msmpeng.exe eating up 100% of my CPU. However, I do not find Windows Defender in my Programs menu, nor can I figure out how to access it through MSE. Would you please tell me how to turn it off through MSE? Thank you.

Cynthia Said,

February 5th, 2010 @7:15 pm

I’m running Windows 7 with Microsoft Security Essentials and I also have msmpeng.exe eating up 100% of my CPU. However, I do not find Windows Defender in my Programs menu, nor can I figure out how to access it through MSE. Would you please tell me how to turn it off through MSE? Thank you.

Kei Said,

February 7th, 2010 @5:09 pm

I found this service in XP under Microsoft Antimalware Service.

Jan Said,

February 11th, 2010 @10:40 pm

I had my cable come out and charge me to set up lightning speed download up…to 40 mbps.

Something is slowing this down and it is not like greased lightning. I have the task manager open right now and it is showing that iexplore is listed 2 times and mem usage is 96,164K and 10,676K. How do you know what programs are running and slowing down the computer? I don’t want to delete something important

les Said,

February 19th, 2010 @11:05 am

Thankyou kei i found it under antimalware services.For people as green as me.Press start button >run> type in the box msconfig takes you to system configuration window open tab services uncheck antimalware services.It has done the trick for me

Odeho19 Said,

February 26th, 2010 @11:35 pm

This information, unfortunately, isn’t true in my case. I have neither Windows Live One Care, nor do I have Defender running. In my case it’s because I’m using Microsoft Security Essentials, and because of this, my CPU is running right now, @ about 55%. I’d really like to decrease this by at least half, but when I open MSE, there appears to be no way to do this…….Ahhhh Microsoft,….continuing to suck the life’s blood out of us, one little app @ a time……

todd94590 Said,

March 4th, 2010 @2:54 am

open MSE, under Settings tab there are two areas where you may do this: Excluded files & locations (click Add, then c:\program files\Microsoft Security Essentials) and Excluded Processes (click Add, then c:\program files\Microsoft Security Essentials\MsMpEng.exe).

Be sure to click Save Changes! Hope it works for ya.

Cheers,

Todd in Vallejo

Debbie Said,

March 7th, 2010 @5:16 pm

I’m using Windows 7 with MSE – I followed todd94590’s suggestions and that worked perfectly.

Fran Said,

March 10th, 2010 @3:27 pm

Thank you so much, my PC is now working properly again ! Weird it began only a few days ago, while I am using Defender/Essentials for months but still !

laurancedavidson Said,

March 16th, 2010 @8:48 am

worked for me, was at 49% now i am at 2-4 percent. easy enough directions to follow.. thanks

Some dude Said,

March 26th, 2010 @7:17 am

Uninstall the crap software from Microsoft and that should fix your problem.

pleasehelp Said,

March 29th, 2010 @6:10 am

I am having a lot of trouble and found where I was supposed to check to see what was using the most and it is MsMpEng.exe system. I have read all of this but am not clear on what it is I’m supposed to do. please help me with step by step explanations. I only pretend to know what I’m doing! hehe
Thank you for your help

address4 Said,

March 29th, 2010 @9:33 am

I am again having this same problem. MSMPENG exc eating all of my processor time. I can’t find Windows Defender on my computer. I had it at one time but it is gone. I use MS Security Essentials. Could it be in that program? If not how can I get it out of my system.

address4 Said,

March 29th, 2010 @9:58 am

Other research shows that this is also in MS SE. Yesterday My SE would not up date. It got to 85% and said no connection. I had to remove and re-install it. Now my processor takes forever to load other programs and hard drive runs around for ever. Eventually it will cause my hard drive to wear out. Magic Jack will no longer load as it battles MS MPENG.

I have to unplug Magic until MS MPENG gets through and then plug in Magic Jack. When will the security people not try to gram all of the processor on boot up? There’s several that I will no longer use. Web Root is one. It seems sometimes it would be better to let the viruses come on in than to continually baby the security programs pop ups, processor seizing, etc.

Does anyone know how to set the processer speed for MSENG from Normal to Below Normal or Low. Task Manager will not allow you to do this. I can turn it off but then I get the annoying popups immediately sayin I am not protected. I don’t need this kind of protection. Does anyone know a good security program that does not grab all of the processor at start up? When you have two programs that do this then neither can load.

Kevin Said,

April 10th, 2010 @4:15 am

If you use Windows XP, just remove this folder: C:\Program Files\Microsoft Security Essentials\

…I wanna Google Chrome OS!!! Sergey, Please!

Deborah Said,

April 13th, 2010 @3:56 pm

I don’t have a desktop icon for Windows Defender – how/where can I find it to set the restrictions????

Asylum1358 Said,

June 3rd, 2010 @4:46 pm

I have the MsMpEng running on my computer, but I don’t have Windows Defender or Windows Live One Care. My laptop originally came with Vista, but I changed it to Windows XP. How do I get rid of it now?