Kernel Usage at 50% yet system idle process shows 100% idle.

My media server running XP Pro SP3 has been sluggish and every time I look in my task manager all processes across all users show 0% CPU usage, however the total CPU Usage is always 50% or so (split evenly across 2 cores, it's not just one core locked up)

I've tried procmon and system explorer but they all show the same thing, 50% overall CPU usage and everything in the process list shows 0%.

When I enabled "Show Kernel Times" in windows task manager and look at CPU usage graphs almost the entire graph is red so apparently 99% of this is happening inside the kernel.

Is there anyway to find out what threads it's running or get some kind of breakdown of the kernel's activity in terms of what is keeping it busy?
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johnb6767Connect With a Mentor Commented:
Process Explorer for Windows

Double click the offending file. If it is a svchost.exe, then Select the Services Tab. Please list what services are in that svchost.exe.

Then Select the Threads tab, and see what .exe or .dll is using the CPU, and then select it by double clicking it....and copying/pasting the call stack here.....

What I would be curious to see is the Interupts, and the DPC's in Process Explorer. If thats what is using the CPU (not seeen in the Task manager), then you have either a HW problem, or a Driver problem.
I would disable devices until you see the CPU behave normally after a reboot. Alternatively, you can remove devices from the device manager, and allow them to reinstall on boot with freshly DL'ed drivers, including the Chipset, Sound, Display, Printers etc...

And unplug any USB/Firewire devices while you are at it...
DailyDilemmaAuthor Commented:
Okay I opened process explorer and the 50% is coming from DPC's (never heard of a DPC). Nothing on interrupts. I tried to view the threads on DPC's and it gave me a "you need a file to view these properly message" which I hastily clicked and now it won't show me the threads and I can't remember the file I need.

I'll restart it and see how that goes, this server runs TVersity, FTP, IIS, SQL Server, File Sharing etc. so I hope restarting it isn't how I'll always have to fix it.
DailyDilemmaAuthor Commented:
Restarting it fixed things, so I'll have to wait for it to show up again and figure out how to get Process Explorer to break down the DPC's for me. Thanks for pointing me to process explorer, tried everything like that and it looks like the best utility of the bunch.
Normally, you dont need the windbg file, as you can *usually* get what you need....
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