I see my machine freezing and struggling for cpu resouce very often and its so annoying every few mins when I am working. I see the process thats eating up CPU is always System Idle process.

There are so many processes hooked under System Idle on the office machine.

Is there a way to find out which one of these processes under System Idle is the killer.
Is there a way to let System Idle run when the system is really Idle not when the user is working on the system ( switching between apps, writting code in visual studio... etc )

I am Running windows XP OS with SP3 , 2.1 Ghz 2GB Ram


Bear in mind that the CPU usages are averaged across all processor cores but most programs do not make efficient use of all cores. For instance if you have a dual core processor and you are running an intensive application that is doing most of its processing in one thread, the application's process will not tend to show more than 50% CPU usage. In this case the System Idle process will be around 50% and this is normal.

If you are having serious problems there are lots of things you could try:

Check for viruses, rootkits etc. using a decent security software suite.

Check system performance settings: right click on My Computer and choose Properties. Click the Advanced tab then click the Settings button in the performance section. The Advanced tab has a number of options including processor scheduling. The options are normally set to give priority to programs rather than services.

Run a disk check on your hard drive(s). It is also worth checking the drives(s) S.M.A.R.T data using a program like Everest Ultimate since a failing drive can cause the kind of symptoms you've mentioned. I know because I have experienced it myself.

Try disabling any non critical programs running in the background (e.g. virus scanners) to see if it makes a difference


When the System Idle process shows a high %, it only means all other processes are blocked, waiting for something else (paging, I/O, network connectivity, ...).

My system also appears to freeze a lot, especially during startup. I suspect the anti-virus software, but I don't really know.

  • +1 for mentioning that processes may be blocked or paged out – Josh Nov 6 '09 at 13:14

Process explorer is nice tool for your help. It will show you all the process list in tree view (Parent-child format).

I'm not sure though on following, but I think CPU percentage shown by System Idle process is the percentage of CPU available to be utilized or which is not being utilized by any process.


seems runnig the check on performace counter on the machine does give a good insight on whats causing the machine to loadup. I found outlook and office communicator eating up my machine resource's. reducing the pst file size from 5GB to 500MB did it for me :)

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