Mysterious CPU usage

from WinCustomize Forums

Over the last week, at random times, one of my CPU cores has been running at 100%. During this there's nothing in Task Manager (System Idle Processes running at 97%-ish, but one of the cores in the 'Performance' tab running at 100%...), no disk activity, no network activity. Numerous scans for viruses, spyware, crud etc are all clear.

It is all a mystery - any suggestions welcome   

3,824 views 11 replies
Reply #1 from WinCustomize Forums Top
WWW Link

Did a google search Fuzzy

Not sure that it will help at all, but posting all of your system info, OS ect may help. Have you checked msconfig for startup programs? Type in Run msconfig hit ok & look at the startup tab.

Also in task manager select to view Handles, Brad wrote an article on that

It's My Secret

Reply #2 from JoeUser Forums Top
Hmmmm...I'm guessing you've already run Hijack This?
Start11 - Customize the Start Menu and Taskbar in Windows 10/11.
Reply #3 from WinCustomize Forums Top
I have had a similar cpu usage. It was caused by windows Defender. It only done it a couple times a day though. So i uninstalled it and cpu usage went back to normal. I never did see the mysterious cpu usage again.
At least that was my problem. GOOD LUCK FINDING IT.
Reply #4 from WinCustomize Forums Top
Windows Defender is probably the culprit. It runs in real time as your Av program does and bogs everything down when it does its "whatever". I uninstalled it the other day when I found that it was causing the conflict on my system.
Reply #5 from WinCustomize Forums Top
WWW Link

Run it and see what's tacking the CPU. When you find it, set Affinity to CPU0/CPU1
Reply #6 from WinCustomize Forums Top

Thanks for the replies:

There's nothing starting up that shouldn't be
Hijack This is clear
I uninstalled WD a while back

I've installed Process Explorer and will now sit back until the next time it does it   

Reply #7 from WinCustomize Forums Top
I read of WindowsUpdate bugging the CPU the other day. There is even a patch for it.
Reply #8 from WinCustomize Forums Top
Lol I had that problem. I also manually fixed that, too.

How to fix my problem: Remove the CPU, clean it out. If you are using a heatsink, put new temperature paste onto the CPU, put it back in, close it up. If not, put your CPU back in and put your cooling system in, and voila: You should not have the problem.

Also, reboot your computer. If you are one of those people who do not turn there computer, off, that will be your problem. There IS memory leaks, registry overload and god know what else. So just reboot your computer, it will erase everything in your RAM, causing everything that is taking space on your CPU into your RAM. Speeds it up alot.

Also, if you are using something like Limewire, exit it. It is a memory hog. Only use it when you have to.
Reply #9 from WinCustomize Forums Top
Process Explorer says 'Hardware Interrupts' 43%. I don't seem to be able to do anything to this except reboot   
Reply #10 from WinCustomize Forums Top

How to fix my problem: Remove the CPU, clean it out.

Reminds me of the April 1 report by ABC2 years ago in Oz...that Telecom Australia needed to clean out the phone lines...and was going to issue all households with a brown paper bag to put over the telephone receiver...and they'd use a high-pressure blower to clean the dust....to be collected in the bag.

Sounded like a plan....

Reply #11 from WinCustomize Forums Top
'Hardware Interrupts' 43%.


I once had the exact same problem on my XP-Laptop. In my case the culprit was a PCMCIA Wireless-Network card by Siemens. I tried to uninstall and reinstall that thing again and again, but to no avail. When I contacted Siemens about it, I only got the "there have been no problems reported with this card.."-answer.

I am still not sure whether it was just one of those strange hardware-clashes or whether the card itself has been faulty, as I have given up on using wireless with that laptop.

hope you find your culprit