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Diko.bg
Diko.bg
Known Participant
March 22, 2017
Question

MsMpEng.exe tremendously slowing LR

  • March 22, 2017
  • 2 replies
  • 1832 views

Hi everyone.

Just wanted to inform you about weird glitch. My Windows Defender (WD). The process/file name MsMpEng.exe began utilizing constantly about 12% CPU (i7-6700K). Couldn't use LR (6.9) at all. Any operation (e.g. spot removal or even next picture view) would take up to 3 minutes. The weird thing is that WD did not slow down my system (Win 10x64). I hardly recognized that WD is active all the time after thorough investigation. Thought it is just another scan, which however was not the case even after disabling the WD real-time protection.

Solution:

After researching the possibility for infection and found no infection (kind of have been in AV field for some time so know a few tricks) I checked and found that

  • the WD program folder must be excluded. C:\Windows\Windows Defender\ or C:\Program Files\Windows Defender\
  • As well as some false positives I am aware of (a few hacking tools, for which I never have the time to test).
  • Restart & observe if MsMpEng.exe is still using CPU without stopping. If not - check if LR slowdown is rectified.

Do NOT:

  • Stop WD permanently - unless planning to install some serious alternative protection
  • Edit any registry files - as long as you are sure about your files

Why and how did this happen?

Simply all began after another Win update.

I write this for anyone that might experience the same problem.

This topic has been closed for replies.

2 replies

E
ericl77314799
Participant
February 14, 2018

Msmpeng process can slow down your whole computer not just LR. You can fix this issue by checking out the solutions at the below site.

antimalwareserviceexecutable.xyz

B
bob frost
Inspiring
February 14, 2018

I exclude my LR previews, LR catalog and settings, nefs, acr cache, etc from Defender scans.

Bob Frost

    Diko.bg
    Diko.bgAuthor
    Known Participant
    February 14, 2018

    Think this would be a good idea. One could add the LR catalog folders as well. However in the LR 7 series - things have improved hugely - so not that much of an issue anymore.

    ManiacJoe
    ManiacJoe
    Inspiring
    March 23, 2017

    Seems odd to need to exclude your WD folder.

    You might want to send a note to Microsoft about this.

    I have my pictures folder excluded. Not sure if that actually helps anything or not.

    Diko.bg
    Diko.bgAuthor
    Known Participant
    March 23, 2017

    If I were you I wouldn't exclude the pics folder, since there are viruses that can and do utilize photo extensions like that one.

    As for the WD. Don't know why. However they will ask me to provide full sys info plus dumps, debug logs (AV program debugging is quite extensive and therefore exhausting). Honestly not quite the fan of that. After all it is supposed to be a protected program folder (not that it's perfectly safe) location. ;-)

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