Windows 10: Update Settings causing high CPU usage from Windows Defender

Recently whenever I open up Update & Security in Settings, it causes Antimalware Service Executable (aka Windows Defender) to flare up in CPU usage by 10-15% and slow down everything else on my computer for the next 10 or so seconds. If I back out into the Settings menu and click on Update & Security again, I won't get the CPU spike + slowdown but if I close out of Settings and click on Update & Security it'll happen again.

This has been happening for the past few days; while I haven't explicitly paid attention to this before in the past, I'm fairly certain that I would have noticed if it had happened before.

Nothing else has slowed down my computer like this, not even games running at max settings. In fact, games actually use up more than 10-15% CPU but don't slow down my computer at the same time.

I've ran sfc/ scannow and malware scans which both came back clear. I don't get the slowdown when "Real-time protection" is off, but that's moot considering Defender isn't even on anymore at that point.

Is this happening to anyone else? Is this the result of some botched definition update? Is there a way to exclude update components from Defender? It may be inconsequential, but I'd still like to get some feedback.

:)

 

WIN10 1703 update cause Explorer.exe high CPU usage

Hi,



Glad you reached out. First, we would like to know if Explorer.exe
is the only cause of high CPU usage. Because the common cause of high CPU usage are the following:

- Windows 10 Memory leak after the update.

- Driver incompatibilities after the update.

- Multiple startup applications

• 
  

We'll be waiting for your update.

 

WIN10 1703 update cause Explorer.exe high CPU usage

I am using Surface Pro 3 (i5, 8G RAM)

After WIN10 v1703 update, Windows Explorer uses ~30-40% CPU.

If I uncheck "Show thumbnails instead of icons" in the Performance Options, the CPU usage of Windows Explorer reduces to ~0%

Any suggestion why showing thumbnails cause so high CPU usage in v1703?

Thanks!

 

High cpu usage caused by tiworker.exe

I noticed this today, too. I was not doing anything, Chrome was open but on a static page. Closed Chrome and still noticed high CPU usage. Sort Processes by CPU and it was bouncing 20-30%. Reading that it is the update process so I ran Windows Update
and there were no updates. I did not look at network activity but CPU Usage declined a little but WTF is is still using so much? And why is it ALWAYS running?

"Critical" suggests it will crash the system if terminated. I killed the process without any issue.