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

Jumping out of the frying pan and into the fire has been banned by the U.S. Cliches Administration as of 1/1/13.

frankly I am amazed that the problems regarding windows defender hogging CPU appear to be so well understood that Microsoft have not "fixed this", but rather pour out instructions how us "Poor bloody infantry" as an old infantryman would say, are left to rummage through any number of avenues to rectify the problem - what wrong in issuing a patch???

That stuff is killing all my gaming sessions with the lag, constantly taking over 20% of my cpu usage.

Ironically this "antivirus" is basically "an unwanted program that uses a lot of the computer's resources", which would make a pretty good definition for a virus.

The worst thing is that even with admin rights I am not able to kill it through the task manager. Ridiculous.

Microsoft won't remain the preferred gaming OS at this rate.

The easiest way I have found to remove this without damaging anything (with there being no way to remove the program entirely) is to just go in like the main response says. Windows Key > Settings > type in "Administrative Tools" > Open Task Scheduler.

From there Navigate via Task Scheduler Library > Microsoft > Windows > Windows Defender.

In this screen you should see 4 tasks in the center of the screen above a larger box. There are three ways to handle this. You can either directly disable all four tasks by Ctrl + Clicking all 4 > Right click > Disable; you can go in through the options and uncheck all the active boxes through all the settings tabs; or you can take my favorite route and delete all the tasks entirely which does not crash your computer, change any other settings, or cause any major problems. It simply stops Windows Defender entirely and removes the issue of the executable taking up so much CPU and disk. To delete all four simply Ctrl Click all 4 > Right Click > Delete. Since doing this I have had no issues, I run a third party Anti-Malware software (which takes up 1% or less cpu during non-scan hours). And the dreaded Antimalware Service Executable takes up under 1% cpu all the time and no disk along with sub 100mb memory.

Hope this helps someone.

The easiest way I have found to remove this without damaging anything (with there being no way to remove the program entirely) is to just go in like the main response says. Windows Key > Settings > type in "Administrative Tools" > Open Task Scheduler.

From there Navigate via Task Scheduler Library > Microsoft > Windows > Windows Defender.

In this screen you should see 4 tasks in the center of the screen above a larger box. There are three ways to handle this. You can either directly disable all four tasks by Ctrl + Clicking all 4 > Right click > Disable; you can go in through the options and uncheck all the active boxes through all the settings tabs; or you can take my favorite route and delete all the tasks entirely which does not crash your computer, change any other settings, or cause any major problems. It simply stops Windows Defender entirely and removes the issue of the executable taking up so much CPU and disk. To delete all four simply Ctrl Click all 4 > Right Click > Delete. Since doing this I have had no issues, I run a third party Anti-Malware software (which takes up 1% or less cpu during non-scan hours). And the dreaded Antimalware Service Executable takes up under 1% cpu all the time and no disk along with sub 100mb memory.

Hope this helps someone.

Unfortunately, none of those “methods” will stop Windows Defender entirely, and everything beyond disabling the Windows Defender Scheduled Scan task is overkill that will just mess up the maintenance tasks. The Antimalware Service Executable (the antimalware engine) is the core of Windows Defender. That process will still be running after you trash the maintenance tasks, and since excessive CPU utilization by MsMpEng.exe is usually caused by a conflict between Windows Defender’s real-time scanning module and components or remnants of a third-party AV app, rather than by the scheduled maintenance tasks, the CPU issue will likely persist.

Installing a third-party AV app is supposed to disable Windows Defender, but if you already have a third-party AV app installed and the Antimalware Service Executable is eating up CPU, then what you need to do is disable Windows Defender itself – not just the Windows Defender scheduled maintenance tasks. That’s the only way to stop Windows Defender entirely. You can do that in the settings in Windows 8/8.1 and you can do it with Group Policy in Windows 10:

http://www.tenforums.com/tutorials/5918-windows-defender-turn-off-windows-10-a.html

Some general guidelines for dealing with this issue can be found here:

http://answers.microsoft.com/en-us/protect/forum/protect\_defender-protect\_scanning/how-to-stop-antimalware-service-executable-from/a3a57d31-4687-43c0-b274-261da7d89245

GreginMich