View Full Version : CPU load / 100% usage for MsMpEng.exe (Microsoft Security Essentials)

20-01-2010, 07:56 AM

After the CPU usage kept spiking to 100% and sitting there sometimes for several minutes, I decided enough was enough, and I was going to get this sorted. So I contacted Microsofts' MSE Support:

Told them about the issue, and got the following in response:

Dear Chilling_Silence,

My name is Ajit and I am with the Microsoft Security Essentials Technical Support team. I'll be assisting you with your case today. For your reference, the case number that we will use while working on this issue is --1234567890--.

From your case description, I understand that the CPU usage goes to 100% in your computer.
If I have misunderstood your concern, please do not hesitate to let me know.

Chilling_Silence, I would like to apologize for any inconvenience that this issue has caused. I assure you that we will work together until the issue is resolved to your satisfaction.

Please check in TaskManager which process is taking the maximum resources.
If its MsMpEng.exe ,then this issue may be caused as MsMpEng.exe service value is not set to Zero in the registry

To check for the exact issue, we need to add the MsMpEng.exe process in Microsoft Security Essential Excluded process list.
To do so, please perform the below steps:
1. Open Microsoft Security Essential program.
2. Click on Add button.
3. Select the path c:\program files\microsoft security essentials\MsMpEng.exe
4. Click ok.
5. Click on Save changes.
6. Close Microsoft Security Essential program.
7. Restart the computer.
After restarting the computer, please check the usage of MsMpEng.exe service in the Task manager window.

If the same issue persists, please send the log files of Microsoft Security Essentials program to do a research on this issue. I appreciate your cooperation in this regard.
1. Please navigate to the following location:
C:\ProgramData\Microsoft\Microsoft Security Essentials\Support\
2. Click Select All the files
3. Do a right Click on the Selected items and Click Copy
4. Paste it in a different folder and zip it and send the zipped file to us.

Note: If you find the C:\ProgramData to be hidden, follow below steps to enable hidden files:

1. Close all programs so that you are at your desktop.
2. Double-click on the My Computer icon.
3. Select the Tools menu and click Folder Options.
4. After the new window appears select the View tab.
5. Put a checkmark in the checkbox labelled Display the contents of system folders.
6. Under the Hidden files and folders section select the radio button labelled Show hidden files and folders.
7. Remove the checkmark from the checkbox labelled Hide file extensions for known
file types.
8. Remove the checkmark from the checkbox labelled Hide protected operating system
9. Press the Apply button and then the OK button and shutdown My Computer.
10. Now your computer is configured to show all hidden files.

Also, for further research I require contents of you a particular Registry Key. Basically we are trying to figure out which installed application on your computer is causing this problem. It would be great if you can export and zipped registry file and send it to us .

Follow these steps to open registry editor.
1. Click on start > All programs > Accessories > Run.
2. In run dialog box type regedit
3. Either press enter or click Ok button on the run dialog box

Registry Key to navigate:
"HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersion\Uninstall"

Please right click on "Uninstall" and select "Export".
Please save the file as "registry.reg" on your desktop and send it to us.

Meanwhile, please be assured that I will be glad to assist you in answering any questions regarding any technical issues with Microsoft Security Essential.

Please try the above suggestions and let me know the results at your earliest convenience. If any of the steps are unclear or if you have any questions regarding the steps, please feel free to let me know. I will follow up with you as soon as possible.

I look forward to your reply.

Thank you for choosing Microsoft Security Essentials Technical Support.

Best Regards,
Microsoft Security Essentials Technical Support
Note: My name and Support ID have been changed

+1 for MS! Now, to see if that first part works. Time will tell :)

Anybody else have similar issues where you notice in task manager that it's taking up all your CPU, then I'd be keen to hear how you go.



20-01-2010, 08:02 AM
Good one Chill :thumbs:

The "spikes" appear to happen a lot in XP.

Might be a good idea to sticky this just for the meantime so others can see it more easily and try it.

Speedy Gonzales
20-01-2010, 08:28 AM
Yup its not as bad in win7 as it is in XP. One program I have noticed that it does "hit" is trojan remover. Which I cant test on this, because TR isnt compat with 64 bit. If you load TR, scan, or update TR. You'll see MSMpEng.exe's CPU usage rise. Which is why (at the mo), it isnt installed on the PC with XP on it (it used to be)

20-01-2010, 10:41 AM
I've tried it on an XP SP2 machine, and a Win7 64-bit Ultimate machine .. thus far all is happy, but really need to give it another 24-48 hours before I know for sure.

Speedy, if it's complaining about TR, I'd use the link I posted to submit a "support" request to them and comment about it :) I'm impressed they actually *did* get back to me. Took 36-48 hours, but still :p

20-01-2010, 11:02 AM
Great! I've had a heap of CPU usage issues with MSSE, have almost gone off it. Will definitely be trying this. :thumbs:

20-01-2010, 11:03 AM
I've seen the CPU usage go up a little bit here and there, but presumably just as it's scanning a specific file? It's only doing it for less than 2 seconds so I'm not concerned :D Seems good!

Speedy Gonzales
20-01-2010, 05:33 PM
Hmm looks like express gate can make booting into windows longer as well. I had it on auto in the BIOS (but cant use it anyway). Since it doesnt work in AHCI mode (which is enabled). I disabled it. And it didnt take as long (after it says welcome). To get into windows

20-01-2010, 05:39 PM
There is a step missing

To do so, please perform the below steps:
1. Open Microsoft Security Essential program.
2. Click settings tab
3. Excluded files and Locations
4. Click on Add button.
5.Select the path c:\program files\microsoft security essentials\MsMpEng.exe
6. Click ok.
7. Click on Save changes.
8. Close Microsoft Security Essential program.
9. Restart the computer.

20-01-2010, 08:52 PM
Thanks gary67. How's that working for you? I've been cruisy all day :D

Speedy Gonzales
20-01-2010, 09:17 PM
Well I thought MSSE may have been the cause of windows 7 being slow booting into windows. It isnt. I tested this by reinstalling Win7 on another hdd. And MSSE wasnt even installed. It was just as slow, with or without MSSE. Vista was faster booting, than Win7, when MSSE was installed. With exactly the same amount of programs installed

21-01-2010, 06:37 AM
I'm running a scan now on Win 7 with VLC, FF & Outlook open and sitting around 49% will check the XP machines tonight

Terry Porritt
21-01-2010, 02:02 PM
I tried excluding Rmvtrjan.exe, the program for starting Trojan Remover gui in My WinXP Pro. The start up time for Trojan Remover dropped from 26 seconds to 18 seconds. It still seems slower though than before MSSE was installed.

Speedy Gonzales
21-01-2010, 02:15 PM
Disable random file generation it'll probably load faster. Since TR changes names. I wont be reinstalling MSSE on this old PC, with TR on it. Its not that fast anyway

Terry Porritt
21-01-2010, 05:09 PM
Disable random file generation it'll probably load faster. Since TR changes names. I wont be reinstalling MSSE on this old PC, with TR on it. Its not that fast anyway

Enabling or disabling random file generation makes no difference to startup time on my setup. It isn't an excessive startup time, just noticed that MSSE slowed it down a bit.

Speedy Gonzales
21-01-2010, 05:19 PM
Yup I know it slows TR down in XP. Which is why I didnt install it again. I've only got TR and malwarebytes on it. Its not connected to the net all the time (only when I update these 2 and windows). So, it shouldnt matter if its got an AV program or not.

21-01-2010, 05:29 PM
Got another follow-up email from Microsoft, a personal one (Not a pre-packaged template). I'm impressed by the service, that's for sure!

21-01-2010, 06:42 PM
SWMBO's XP home machine was just defragging and running a MSSE scan the CPU usage was at 19%. not bad as I had already made that recommended change this morning so I'm happy with that

21-01-2010, 09:38 PM
Thanx for the info guys. I had this on a new install at work yesterday. Removed it and tried Avast 5 instead..

22-01-2010, 03:25 PM
seems the win 7 still not good than xp

22-01-2010, 09:19 PM
I'm sorry, what do you mean jellyliu?

I got a phone call from MS today asking if they could close the case and mark it as resolved. I suggested they add it by default to the excludes list :p

10-02-2010, 09:29 AM
Ive had no issues with MS security untill I put it on a Vista PC(clean re-install).
Cpu usage went up to 65%, even opening controll panel or add/remove seemed to trigger an AV scan of files in use/being opened. Made the PC unusable.
I had to come off. Seems another MS product not fully tested/debugged before release.

12-03-2010, 10:57 AM
I tried the fixes with the exclusion list but that made no difference. What nailed it for me was to run Norton uninstaller (http://service1.symantec.com/support/tsgeninfo.nsf/docid/2005033108162039)
This PC is a Compaq which I had restored everything back to factory settings using the its' recovery partition. Of course it must have come bundled with norton, so all that was re-installed as well.
Uninstalling using add/remove didn't clean it up enough apparently so I downloaded & run the norton tool.
It's amazing how much of a relief it is not to hear the churning of cpu & disk read/write etc. Quiet as a mouse now...you beaut!
Research with google suggests this problem cause varies but I hope this helps someone.

02-04-2010, 11:56 AM
There's the recently released application update which seems to have resolved the issue here. Anybody else?

12-04-2010, 11:16 PM
Good one mate!:clap

12-04-2010, 11:44 PM
There's the recently released application update which seems to have resolved the issue here. Anybody else?

So do you have an issue as to MSE at this time?

If so then what?

13-04-2010, 11:14 AM
Yes, CPU usage is *still* incredibly high (though admittedly better now after this update) by comparison to the likes of Avast Anti-Virus, and it interferes significantly at times with gaming :(

13-04-2010, 12:13 PM
OK CS. I was just curious in so far as I have found MSE to be fine for me on my rig which is somewhat outdated now.

AMD 4400+ with 2 Gig RAM and dual booting Win 7 Pro and Debian Linux.

I have to admit that Avast worked fine as well and I was running it up until MSE came out.

There again I'm not a gamer as such unless you count MS Flight Sim 2004 and I'm not even running add ons and extra scenery ( mesh ) for that.

13-04-2010, 03:46 PM
32-bit or 64-bit?

Speedy was saying the issues gone for him now in 32-bit I believe?

I've switched sides, I bought a Macbook, so no anti-virus there, but unfortunately my wife still has Win7 on her laptop, as do many of my clients, so I have to be able to offer advice on a reliable solution :p

Flight Sim is still relatively resource-intensive isn't it?

11-05-2010, 10:58 PM
Thanks for this help Chilling_Silence. I came on to PressF1 tonight to check out some help for just exactly this problem and there was your solution right before my eyes. It has worked a treat and the old machine has quietened down significantly and speeded up somewhat. Thanks again.

11-05-2010, 11:13 PM
Sorry CS. I missed your post #28.

Win7 64 pro.

I'm still running MSE BTW.

12-05-2010, 10:23 AM
Mine still hits the roof from time to time, but to be frank I think it's going through all my archives (Zip / RAR) and whatnot, rather than the realtime scanner. Because I've got several TB of data, it wouldn't surprise me if it spent half the week trying to recover from its weekly scan on a Sunday :p

Glad we could help advena!