Windows 10: Programs Slow To Open Due To Windows Defender (MsMpEng)

This is something that I've noticed since Windows 8, but Windows Defender make some programs so slow to open. It's pretty noticeable on the programs that it does it on as it takes approx. 20-30 seconds to open them, even from an SSD, and if you look at Resource Monitor listed by CPU usage, you can see it's due to MsMpEng.exe running a scan before the program will open.

It would be understandable if it was doing it the first time the program had ever ran, or if the program wasn't signed, but that's not always the case. Canon DPP for example isn't signed, so presumably that's why Defender keeps scanning that, however here's an example of another program (SyncBackFree) that is signed, but yet Windows Defender still wants to keep scanning it on a daily basis despite nothing changing since previous scans.





Obviously I can add individual programs to the Windows Defender Exclusion list and exclude them from real-time protection, but what it is that Defender doesn't like with certain programs that is feels the need to keep scanning them daily? Is this a Microsoft problem, or is it down to the software not adhering to some sort of best practice policies Microsoft have laid out? There must me something that makes Defender treat it as potentially signed malware?

:)

 

About Windows Defender!

Pardon first my English.

I just can't open Windows Defender. When I try to open it, it ends the task and it disappears from the taskbar, please help me!

I also have the latest Windows Defender update. Maybe is this the problem?

And I had the 30-day trial McAfee anti-virus protection, which today when I updated the windows Defender program, McAfee didn't open up, and then Windows defender stopped working only in the
foreground, but in the background there's a service that is called ''Antimalware Service Executable'' and it's the ''MsMpEng'' program which is located in the Windows defender folder. When this service runs in background my CPU stats are going
till 100%, when I open the task manager my CPU stats are going to 2%. Why this is happening? Please help me!

***Post moved by the moderator to the appropriate forum category.***

 

Off the chart (literally!) disk usage

Did you run wpr -cancel from an admin cmd prompt?

Also try setting Diagnostic and usage data under Settings app > Privacy > Feedback & diagnostics to
Basic.

MsMpEng is Windows Defender and lots of people have complained over the years about its high resource usage and slow speeds. The suggestion that you read about to switch to a better AV is perfectly valid.

If none of the above helps, open services.msc and try stopping and disabling the DiagTrack service.

 

Im confusing too ... some program are so SLOW because of Windows Defender

 

There is a slight delay, yes. I tried AVAST and it was a lot worse.