System maxing out CPU

It happens intermittently and causes TF2 to lock up for the duration (unthinkable!).

I really have no idea what stuff falls under the System process so I don't know where to look for causes, though I have done spyware and virus scans with multiple programs.

I attached a picture of it occurring with task manager and resource monitor.


Edit: I heard about process explorer and was able to find that the thread that was causing the problem was spawned by ntoskrnl.exe.

Run process explorer to figure out what is causing the problem.

http://technet.microsoft.com/en-us/sysinternals/bb896653