CPU usage 100%

[stuartjohn]

My laptop Toshiba Satellite A100 has a CPU usage of (near) 100% continuously.
I have been trying to determine which process could be responsible, without success. I also switched off the network connections, also without result.
How can I find out the reason for this load and correct the situation ?

 

[ko888]

Which Operating System? I know that the Toshiba Satellite A100 was originally sold with Windows XP Professional but you might have upgraded since.

The Task Manager should be able to show which process(es) may be consuming all of your CPU resources.

 

[stuartjohn]

O.S. is Win XP Home, 2002 edition, service pack 3.
I did check the task manager and closed all processes I thought unnecessary, to no avail.

 

[ko888]

Was the Show processes from all users check box checked?

 

[stuartjohn]

Yes, it was checked. Still is.

 

[ko888]

What are the names of the processes taking up all of the CPU resources?

Post a picture of your Task Manager window, it might help.

Another tool I use is Process Monitor from Sysinternals that helps me determine what is going on in Windows. I can see what the registry , file and network activity is being done by each process.

http://technet.microsoft.com/en-us/sysinternals

 

[stuartjohn]

Thanks, I will try that.
I've not found out yet how to copy the picture of the task manager.
Meanwhile, I let AVG run a rootkit scan and it found 3 infections, which have been quarantined. After reboot the the situation remained as before (100% cpu usage), but all of sudden that dropped to a normal 0 - 7 % ! It has remained there since.

Could it be the rootkits claiming all that cpu resource ? I did not notice any extra network traffic during this all.

Anyway, thanks again for looking into this.

 

[ko888]

Yes, rootkits can slow a system down to a crawl.

 

[stuartjohn]

It appears now that the problem was not with the rootkits. Process Monitor revealed that a service belonging to a driver program to connect my mobile phone to the laptop, named Moto Helper service was using up nearly 100 % CPU time. The service could not be stopped by Task Manager so I uninstalled the driver. Everything points to a corruption of the hard disk, since removing the program I discovered that the sound drivers are now unable to load.