Reference number: CH000616

Windows system CPU usage continues to peek or stays at 100% 

Issue:

Windows System CPU usage continues to peek or stays at 100%.

Cause:

This issue can be caused by any of the below possibilities.

1. Other programs being run in the background.
2. Computer Trojan, Virus, Worm, Spyware or other malicious program

Answers:

Determining what's utilizing the CPU

Each process that is running in Windows and the CPU usage it is using can be determined by opening the Windows Task Manager and clicking on the processes tab as shown in the image below.

Once this tab is open click the CPU button above the list of programs twice to organize the programs CPU usage from highest to lowest.

Note: If you do not see the processes tab your running an older version of Windows that does not have this feature.

As can be seen in the above example we have two processes running that are each taking up 50% of the CPU. The Image names "FahCore_81.exe" and "System Idle Process". It's perfectly normal for a Windows computer to have a high "System Idle Process" as can be found on document CH000729.

However, in this case the other process "FahCore_81.exe" is using up a lot of CPU usage that may be concerning. In this situation we know that this Image name is associated with Folding@Home a distributed systems project. However, if you're not familiar with what the process is doing a search will often return the results of what the file is associated with.

If you need to regain CPU resources temporarily you can highlight processes utilizing high percentages and click the End Process button. However, often after rebooting the computer these processes will reappear.

Permanently keeping the TSR disabled

If you've End Tasked the program following the steps above to temporarily remove the program from starting up but it returns each time you start the computer you'll need to disable that program from starting each time Windows loads. Additional information about closing preventing TSRs from starting up can be found on document CHTSR.

If you are unable to navigate in normal Windows or performing the above steps does not decrease your system resources back to a normal value try restarting Windows in Safe Mode. Additional information about how to get into Safe Mode can be found on document CHSAFE. 

Computer Trojan, Virus, Worm, Spyware or other malicious program

Computer Trojan's, Viruses, Worm's, Spyware, and other malicious programs designed to destroy or modify data on your computer or other computers attached to your computer or designed to attack other computers can utilize your system resources.

Make sure your virus scanner is up-to-date, if you have questions about updating your virus scanner please refer to document CH000533.

Make sure you have a spyware program installed on your computer and that it is up-to-date. If you do not have a spyware program installed on the computer it is highly recommended you install one now. A listing of spyware programs can be found on document CH000578.