System Idle Process Displays High CPU Usage
A lot of users who are not very well acquainted with how the Windows OS works on a more technical level sometimes get a bit of a fright when they see certain processes reporting very high CPU usage. One of the most common false alarms is seeing the System Idle Process reporting CPU usage of over 90%. What does this mean and should you be worried or do something about it?
First things first - if you see your System Idle Process using something like 99% of your CPU in the readings of your task manager, this is usually no reason to be concerned. To explain it in the simplest terms, you should think of the reading of the System Idle Process as "how much CPU do I have available for other tasks on my system?" and not like a normal process.
That is to say, a reading of 99% on the System Idle Process effectively means only 1% is used by the current idle state of the PC and the remaining 99% are free and available in case any other application needs them. This is perhaps a bit counter-intuitive, considering how the rest of the processes report CPU usage, but this is how it works in Windows.
To reiterate, a very high percentage on your System Idle Process is no cause for alarm in most cases and you should not fret over it.
There are, however, fringe cases where you might want to take a closer look at things. If your PC is behaving normally and you experience no slowdowns or performance issues, there is nothing to worry about. However, if you notice your System Idle Process or some other native Windows process such as svchost or the Service Host Process taking up large chunks of your CPU, and your system is slow, laggy and unresponsive on top of that, you may want to take action.
There are types of malware that will hijack, inject themselves or create fake copies of legitimate Windows processes to disguise their activity. If your system is very sluggish and you see strange CPU usage on system processes, you might have some sort of malware on your PC. There are many different kinds of malware that exhibit that behavior so you cannot be certain what the issue is.
Your best bet in this situation is to run your anti-malware suit of choice and go for a complete system scan. Hopefully, the software will be able to pick up and eradicate the malicious files from your system that were causing the slowdowns, while disguised as legitimate Windows processes.
