System process in WIndows XP

We have an XP PRo, SP2 machine, on a domain it has has the following problem. In the task manager under processes a process called "System" (w/out quotes) takes up 75% of the cpu. I cant kill it. I did spyware and virus scans (spybot, housecall, NAV, ad-aware) and found nothing. Why is this porcess taking up some much CPU? and will not stop. I did a scandisk after the event viewer showed a disk error afew days ago, but the error has not occured in a few days and the system process is still taking up the cpu. Any suggestions?

 

http://www.sysinternals.com/ntw2k/freeware/procexp.shtml
Use Process explorer When you open it , go to view and make sure there is a check by View DLLs and see if you can identify an associated file.
I get the impression this is generally the result of a hardware malfunction; often and IDE or SCSI controller.