Services process has my CPU pegged at 100%!

Symptom: Computer is slow 

Problem: Windows Service Process using 100% of cpu

Fix: USB device causing Deferred Procedure Calls to use 40% of cpu

My client had a computer that was bogged down.  Really bogged down.  Click on something and it would take 20 seconds for the computer to respond to the click.  When looking at the cpu usage via task manager I saw that the virus software processes was taking up 100% of the cpu.  Naturally I killed this process and things went back to normal.  The cpu was no longer pegged. 

So I thought this was an easy one, just uninstall the virus software and reinstall it.  Maybe something got wacked with the virus softwares files and just needed a clean install.  So I uninstalled it and rebooted.  Did it fix the problem. No.  After I rebooted the cpu was again pegged at 100%, but this time the "Services" process had the cpu pegged at 100%..  Bummer.  So much for my easy fix.

The Sevices process is part of Microsoft Windows Operating System that manages the operation of starting and stopping of services.  Vague eh, I agree?  For more information on this just do a goolgle search "what is windows services process".  There is lots of info on it.

Since I could not kill the services process (its a core windows process) I had to find out what was causing the services process to go crazy like that.  But with task manager I was limited and I couldn't see what was really going on behind the scenes.  So what I did was got a great piece of software from these guys http://www.sysinternals.com/Utilities/ProcessExplorer.html . 

This program showed me all the details of all process tasking my clients cpu.  What I found was a process called DPC's or Deferred Procedure Calls was taking up 40% of the cpu and in turn caused the Services process to work which sucked up another 60%.

So now I needed to find out what DPC's really was and what uses it.  I won't go into details on it but just google it to find out what its about.  This search lead me to some clues about what might be causing it to use so much cpu.  And the clue pointed me to USB devices, and it was a great clue.  It was a external USB device. 

There where 4 usb devices plugged into the back of the system.  Once I removed the devices and rebooted the system the problem went away.  I then plugged the usb devices back in but in different ports than they were originally in.  Still, nothing.  The problem still didn't rear its head.  So then I rebooted again with the devices still plugged in and nothing.  Problem was still gone.

So what did I do?  I grabbed my coffee and went on to other tasks that needed attention.  Though I didnt find out what device was causing the problem it didnt matter.  Life is short and computers will be around causing headaches forever.  I had other things to do and the computer was working just fine.

The moral of this story is if your not interested in the details (I am not as you can tell), then just get the thing working and go on with your life.  I did and my clients computer is working just fine.