Can one prevent Antimalware Executable to start hogging CPU for extended periods each time some network adapter gets active?

Hello. Yes Windows Module Installer some times runs for a few hours after taking updates or installing a program. But it Rarely pulls more than 18% of the Processor. But this Antimalware Service Executable wants to Pull between 75 - 90% of the processor. I just can't figure out how Microsoft can Justify this. I renders both of my computers USELESS when it is running. That is like Microsoft saying WE Own Your Computer!!!!! What is up with that? I will say it again" Microsoft WAKE UP!!! Release a Hotfix for this Screwup!!! My room mate works in a Computer repair shop. This is the Number 1 Problem that people bring in 8.1 computers for to be fixed!!!! So Far there is no fix for it!!! Several people on this site and on this thread act like they have the answer. But they are Lying through their teeth!!! If you try to shut it down your computer Cuts Off!! And all the steps that people say try don't Work at all. When this little **** kicks in, it's like the ever ready bunny, it just keeps Running and Running! I just walk away, and go use my girlfriends MAC!!! It's all I can do. If I restart it just makes it run longer!!!! Again "Microsoft Wake UP, we are all waiting for that hotfix for this 1". I think Microsoft thinks it is protecting the Operating System, But all it is doing is slowing everything down to a SNAILS CRAWL!!!! It still allows people to install **** like Savings Bull And Spigot Bullcrap, which is Parasite Tagalong software which Kills Windows 8.1. This **** if you install enough of it, the only cure is to Reinstall Windows!!! So Antimalware Service Executable is Really No Help At All!!!!!!!!!!!!!!!!! One More Time " Wake Up Microsoft, and release a Hotfix that will Work" after all isn't Microsoft the update king of the world!!!!!! Microsoft Don't let Team OS make you look really Bad!!!!!!!

They seam to be coming up with fixes faster than Microsoft, that Wrote the program!!!! What's up with that????????

 ****,

 Muchofreeo.

Hello there i've got a problem, i've gone through every step but im lost at step D.

I cant find anything about idel or something like that !  

If Automatic Maintenance is running the Windows Defender scheduled scan while you’re using your PC (if you see the Automatic Maintenance “clock” superimposed on the Action Center icon (the white flag in the notification tray)), and this is interfering with your work, then I would suggest scanning for system corruption:

http://answers.microsoft.com/en-us/windows/wiki/windows8\_1-system/troubleshooting-component-store-system-files/8acbd614-678d-42b9-859c-56d3e6f8342a

If the Automatic Maintenance scan isn’t yielding to user activity the way it’s supposed to, then you can work around the issue by rescheduling Automatic Maintenance (in the Action Center) for a time when the PC isn’t in use, or you can disable the Windows Defender Scheduled Scan task in Task Scheduler (right-click on the task and select “disable"). If the issue isn’t directly related to the Automatic Maintenance scan, but appears to be related to problems with the Windows Defender antimalware engine (MsMpEng.exe) per se, i.e., if you observe excessive CPU usage for MsMpEng.exe (in Task Manager) when the scheduled scan isn’t running, this is most frequently caused by conflicting (real-time) antimalware products, remnants thereof, or by utilities with high read/write activity levels, which can sometimes be identified with Task Manager or Process Monitor. If you see this “free-floating” excessive CPU usage for MsMpEng.exe, the first thing you need to do is remove any other real-time AV products that might be installed, and also run the removal tools for any AV products that were packaged with the PC, or that you previously installed:

http://answers.microsoft.com/en-us/protect/wiki/mse-protect\_start/list-of-anti-malware-product-removal-tools/2bcb53f7-7ab4-4ef9-ab3a-6aebfa322f75

If that doesn’t eliminate the problem, then the issue could possibly be the result of undetected malware, so you should scan with multiple second-opinion antimalware scanners:

http://www.surfright.nl/en/hitmanpro

https://www.malwarebytes.org/free/

http://www.kaspersky.com/downloads/kaspersky-virus-removal-tool

http://support.kaspersky.com/viruses/disinfection/5350

http://www.pandasecurity.com/homeusers/solutions/activescan/ 

http://www.bitdefender.com/scanner/online/free.html

http://www.eset.com/us/online-scanner/

If that doesn’t do it, then you should just go ahead and install a third-party AV product. The Windows 8/8.1 operating system is designed to shut down Windows Defender automatically when any other real-time AV product is installed – and third-party AV products not only seem to be less prone to conflicts; they also appear to have better detection rates:

http://www.av-test.org/en/home/?avtest\[type\]=3

But be advised that the final verdict isn’t in yet, because the analysis changes radically when it’s based on Microsoft’s own prevalence data:

http://www.av-comparatives.org/microsoft-prevalence-based-analysis-file-detection-tests/

GreginMich

I have admin rights on my Win8 pc, and in the Task Scheduler **Library/Microsoft/Windows/Windows defender,**the condition "Power" has a checkmark but it is greyed out so I cannot remove the checkmark. how to "ungrey" this condition ?

"Click properties on the right hand side of the window."

I don't understand how you fail to find what I just found in 2 minutes.

Very helpful Spazz!! I'm still none the wiser!!