Whenever my winxp home rig starts freezing up, I usually do a ctl-alt-delete and go to the processes tab. Over 90% of the time, something called System Idle Process is taking 80-95 CPU. What is that, why is it doing it, and how can I fix it?

I googled the problem. Others seemed to have the same problem as me, but other people answered that it wasn't a problem at all. They said that the System Idle Process in NT based windows is the lowest level priority program and should never mess up your comp. Yet for me, and a couple others, it does.

all that does is just a way of saying how much proc time isn't really used. I have never had an issue with it.

That's what I thought. But if my comp is froze, shouldn't it say 0?

Not necessarily. It may have been something like explorer.exe crashed but didn't really crash and it just stopped responding. As I type this, my system idle process is taking 98 percent of the CPU and everything works fine. The 'idle process' is not any problem.

The "System Idle Process" is not a process, and it is therefore impossible for it to cause any problems. Basically it is just windows adding up all the CPU time it spends actually doing something, and then subtracting that from how much it could have done (so all the CPU usage % are just added up, then subtracted from 100)

What COULD be happening is that your system has "hung" on something else. It if fully possible for a program to be waiting on the hard drive or network, and appear frozen, yet not actually be so. It is common for the GUI to 'lock up' in a non-multi-threaded application during IO, as the program is just sleeping and waiting for the IO to be completed, and not processing any GUI events as that can lead to a potential 100% CPU usage that isn't doing anything

So the real question is WHAT is it actually hanging on? Try using sysinternal's process explorer, as that shows disk and network IO in addition to CPU usage on a per application basis. That will paint a much better picture of what is actually happening