CPU usage suddenly skyrockets and stays that way

I am having a problem where everything suddenly gets VERY slow. I may be doing anything at that moment; it appears to happen most often when I am surfing the Web with Firefox, but then I do it a lot and this may be just statistical bias. It has happened in other circumstances as well, and likewise, I've had long Firefox sessions without it happening. It is unpredictable - it may happen minutes after I log on, or many hours later.

When it happens and I press CTRL+ALT+DELETE to run Task Manager, just reaching that screen can take several minutes, with the screen all black and the green wheel cursor whirling forever. When I finally get to Task Manager, I see a certain instance of svchost.exe eating up most of the CPU time, as shown in the first screen capture (I caught it at 86% CPU time in this capture, but it can easily reach 99%).

Since svchost.exe is the running shell of a lot of Windows' services, I looked at the running services to see what did that process ID (PID) correspond to. It is a 3-in-1 PID, hosting the DcomLaunch, Plug and Play and Power services, but all three in group DcomLaunch, as shown in the second screen capture.

The only way to get out of this mess is rebooting, as the process will keep going runaway indefinitely, and killing it will result in Windows showing an error message that it has to reboot anyway because the Plug and Play service has stopped running. A scan for malware found nothing.

Any hint as to what may be causing this, and how to solve it? Thanks a lot.

Go to Start > Run,. and type msconfig,. click the startup tab and uncheck everything except for your anti-virus software, spyware detector and personal firewall if you have on.

You can also disable services you don't use nu going to Star > Run ,and type services.msc

Go to Black Viper's site for indformation on sercices:
Windows 7 Service Configurations by Black Viper

Hi, will you go back into Processes and click on the word Memory at the top of the list,
it will bring all the processes that are using the most of your CPU to the top, and then post that picture,Please.

Yes,. I should have included that:)

Msconfig can have a lot of useless entries,.

Removing them speeds up your computer because they don't load at startup/

Trust me, there will be less proccess running

I would do as reghakr suggests and untick all the boxes, except your Anti Virus, in the Start/ Msconfig,
and then reboot.

Jacee said:

I prefer either manual or disabled settings in "Services", rather than msconfg in start up, but each to their own preference. :)

I agree with Jacee. If you use msconfig, it isnt global, services is. Big difference

Ken