Both of those are system processes, which are used to govern OS-level services; they're generally not a problem by default, and you do usually see several instances of them running. That said, I would check what you have installed on that system and see whether or not the system is really cut out to handle it. I have personally traced a lot of problems lately to recent versions of Symantec/Norton utilities packages, including their antivirus programs – it's getting to the point where their software seems to cause more problems than it solves. Also, if you have not defragmented the computer in some time, there may be a performance hit coming from that as well.
This was first published in September 2004